KRAKOW, Poland — Recent from its triumph during the last armed Ukrainian resistance within the devastated metropolis of Mariupol, Russia seemed to be laying the groundwork Thursday for annexing swaths of southeast Ukraine, described by a high-ranking Kremlin official as having a “worthy place in our Russian household.’’

The official, Marat Khusnullin, Russia’s deputy prime minister for infrastructure, toured the area this week and outlined plans to take full management of significant infrastructure, together with Europe’s largest nuclear energy plant, as Russia fortified its defensive positions there and exerted its authority over the native inhabitants.

“I got here right here to supply most alternatives for integration,” Mr. Khusnullin was quoted by Russian information media as saying.

In an extra signal that Moscow was getting ready to push for the Russification of the area — the way in which it has in Crimea since seizing it from Ukraine in 2014 — Russian officers have already moved to introduce the ruble forex, set up proxy politicians in native governments, impose new faculty curriculums, reroute web servers via Russia and lower the inhabitants off from Ukrainian broadcasts.

Mr. Khusnullin stated Russia even meant to cost Ukraine for electrical energy generated by the Ukrainian nuclear plant that Russian forces commandeered within the early weeks of the invasion — a plan that Ukraine described as extortion.

Russia’s strikes got here as the US sought to additional escalate strain on the Kremlin. President Biden vowed to assist acquire speedy approval of functions to hitch NATO by previously impartial Finland and Sweden, as he welcomed the leaders of those countries to the White House and as U.S. officers expressed confidence that they may fulfill Turkey’s objections to Finnish and Swedish membership. And the Senate overwhelmingly approved a $40 billion aid package for Ukraine that Mr. Biden was set to signal into regulation.

Even because the Russian authorities projected management over a Ukrainian area that’s culturally near Russia, President Vladimir V. Putin seemed to be punishing navy subordinates for blunders within the three-month-old invasion.

A report by Britain’s protection intelligence company urged the Kremlin was conducting a purge of senior commanders deemed answerable for the failures of Russia’s preliminary technique to seize rather more Ukraine territory, together with the capital, Kyiv, and second-largest metropolis, Kharkiv. The report raised the query of whether or not Mr. Putin retained religion in his chief of the overall workers, Valery Gerasimov.

The Russians have stated nothing about any adjustments within the navy management.

Credit score…Olga Maltseva/Agence France-Presse — Getty Pictures

Russia’s new, narrower technique of specializing in Ukraine’s east has proved extra profitable than its initially larger goals, whilst its forces have retreated within the northeast and struggled to realize floor within the japanese Donbas area.

Following the longest battle of the warfare, Russian troopers completed their capture of Mariupol on Tuesday after having seized management of the sprawling Azovstal metal plant, the final redoubt of Ukrainian defenders. Greater than 700 fighters from the Azov battalion, die-hards who had made a last stand in opposition to the Russians from the plant, surrendered between Wednesday and Thursday, based on the Russian Protection Ministry, bringing the whole variety of captives to 1,730.

The Kremlin has been utilizing the mass give up for propaganda purposes, describing its captives as terrorists and Nazi warfare criminals, and framing the conquest of Mariupol as a turning level within the battle.

Though a lot of Mariupol is ruined, the seize of the port metropolis is anticipated to deliver Russia concrete advantages. It should full a long-sought land bridge between the Russian-controlled Crimean peninsula to the south and the adjoining area generally known as Donbas, the place pro-Russian separatists have battled Ukrainian forces for the reason that Crimea annexation.

With Mariupol captured, Russian troops at the moment are freed to assist entrench Russia’s authority over the remainder of the japanese area — nicely wanting Moscow’s preliminary push to regulate all of Ukraine, however sturdy leverage in any future peace negotiations.

Credit score…Andrey Borodulin/Agence France-Presse — Getty Pictures

The combating has settled right into a stalemate alongside a lot of the entrance.

Stiff Ukrainian resistance is forcing Russian troops to combat in smaller formations and search extra restricted goals elsewhere within the Donbas area, a senior Pentagon official stated on Thursday.

“They’re going after smaller goals,” the senior official stated of the Russian objectives, talking on situation of anonymity to debate operational particulars of American protection intelligence work. “And typically these goals are solely maintained for a brief time frame earlier than the Ukrainians take them again. They’re simply being extra modest in what they’re making an attempt to go after.”

The shift in Russian ways displays not solely the resilient Ukrainian protection, but additionally the nagging command, logistics and morale issues that continued to bedevil Russian commanders, particularly within the hotly contested Donbas, the official stated.

The southern area underneath Russian management covers an enormous expanse that features Ukraine’s agricultural heartland and several other key ports. Together with Russia’s naval dominion within the Black Sea, annexation would tighten Moscow’s stranglehold on the Ukrainian economic system and solidify its blockade of Ukraine’s southern coast.

In one other potential signal of steps to entrench Russia’s management, its troops closed checkpoints on Thursday for civilians crossing between Russian-occupied zones and Ukrainian managed areas in two areas, Kherson and Zaporizhzhia, based on the Ukrainian navy and native authorities.

Credit score…Olga Maltseva/Agence France-Presse — Getty Pictures

At one checkpoint, close to the city of Vasilyevka, a line of automobiles transporting largely girls and kids in search of to evacuate Russian-held areas stretched via farm fields. Ukrainian officers estimated greater than 1,000 automobiles waited on the crossing, stated Zlata Nekrasova, the deputy governor of the Ukrainian regional authorities in Zaporizhzhia.

The Ukrainians have accused Russia of forcibly deporting hundreds to Russia and witnesses have described more and more repressive efforts to implement Russian rule.  

The Kremlin has sought to painting its actions as reflecting fashionable will. Dmitri S. Peskov, the Kremlin’s spokesman, appeared to minimize the importance of Mr. Khusnullin’s statements signaling annexation, saying solely locals might resolve.

However in a transfer that some analysts thought to be reflecting confusion throughout the Russian management about learn how to safe Ukrainian areas seized by Russia, a bunch of lawmakers on Thursday submitted a invoice to the State Duma that may permit Mr. Putin to determine “momentary administrations on territories the place Russia’s military conducts navy operations.”

Mr. Khusnullin stated that Russia would quickly start charging Ukraine for electrical energy from the Zaporizhzhia Nuclear Energy Plant, which Russia has managed since early March. When absolutely operational, the plant can produce sufficient power for 4 million houses.

Ukraine’s power supplier, NPC Ukrenergo, which referred to as Mr. Khusnullin’s assertion nuclear blackmail, stated the true intention was to provide Russia electrical energy leverage over Ukraine and the remainder of Europe. It famous that the plant was a part of the Ukrainian energy grid and unequipped to ship energy to Russia.

Credit score…Andrey Borodulin/Agence France-Presse — Getty Pictures

Moscow’s bulletins had been additionally a part of a propaganda marketing campaign aimed toward conveying management over areas the place its grip is much less stable. Navy analysts have stated Russia’s forces might nonetheless face Ukrainian uprisings and counteroffensives.

Russia’s invasion in February, spearheaded by a speedy advance of tanks and helicopters, in the end led to many Russian casualties, including some senior generals on the battlefield. The finger-pointing has began, Britain’s protection intelligence company stated in its Thursday report.

It stated the commander of the elite 1st Guards Tank Military, Lt. Gen. Serhiy Kisel, had been suspended for failure to seize Kharkiv, the place Ukrainian forces haven’t solely counterattacked however pushed the invaders again towards the Russian border 40 miles away.

The British company additionally reported that the commander of Russia’s Black Sea fleet, Vice Adm. Igor Osipov, had doubtless been suspended following the April sinking of the fleet’s flagship, the cruiser Moskva. Requested in regards to the report, a senior Pentagon went additional, saying the commander had been dismissed.

Common Gerasimov, Russia’s highest rating uniformed officer, “doubtless stays in submit however it’s unclear whether or not he retains the arrogance” of Mr. Putin, the British report stated.

However in a sign that Common Gerasimov remained in good standing, he spoke on Thursday by cellphone with Gen. Mark A. Milley, the chairman of the Joint Chiefs of Workers, the Pentagon stated. It was their first name for the reason that invasion.

Credit score…Pool picture by Alexei Nikolsky

Within the port metropolis of Kherson, within the south close to the border with Crimea, Mr. Khusnullin inspected infrastructure, together with the port, a cargo railway station and a manufacturing unit.

“We are going to stay and work collectively,” he stated, including that Russia had already allotted funds to revive the town’s roads.

“We are going to now eat tomatoes and tomato paste extra usually in Russia because of the work of Kherson’s agricultural producers,” Mr. Khusnullin stated, alluding to Kherson’s longtime position as a breadbasket and a world exporter.

However whilst he spoke, Ukrainian officers stated a convoy of civilian automobiles making an attempt to flee the area got here underneath hearth from Russian troopers. Roughly half of the million individuals who as soon as lived within the area have fled, with witnesses who escaped providing harrowing tales of Russian repression.

In Kyiv, a committee in Ukraine’s Parliament accused Russia of getting robbed Kherson of 400,000 tons of grain, sending it to Russia and creating circumstances that “could result in famine within the occupied territories.”

A Russian naval blockade of Ukraine’s ports is stopping Ukraine from exporting hundreds of thousands extra tons, placing tens of hundreds of thousands of individuals worldwide prone to starvation and famine, the U.N. secretary normal, António Guterres, stated Thursday at a U.N. convention on meals safety.

Credit score…Finbarr O’Reilly for The New York Occasions

Marc Santora reported from Krakow, Poland, Ivan Nechepurenko from Tbilisi, Georgia, and Norimitsu Onishi from Paris. Reporting was contributed by Matthew Mpoke Bigg from Krakow, Eric Schmitt, Helene Cooper and David E. Sanger from Washington, Valerie Hopkins and Andrew E. Kramer from Kyiv, Shashank Bengali from London, Anton Troianovski from Brussels and Rick Gladstone from New York.