WASHINGTON — President Biden vowed on Thursday to hurry Finland and Sweden to NATO membership, searching for to redraw the map of Europe to the West’s benefit lower than three months after President Vladimir V. Putin of Russia started his invasion of Ukraine.

In a ceremony within the White Home Rose Backyard with President Sauli Niinisto of Finland and Prime Minister Magdalena Andersson of Sweden, Mr. Biden mentioned he was instantly submitting to the Senate the treaty language wanted to make the 2 nations the latest members of the alliance. Formal accession to the alliance would require the approval of the opposite 29 member nations as nicely.

Whereas there’s little doubt that the Senate and most different NATO members will overwhelmingly approve a treaty of accession, Turkey — which below President Recep Tayyip Erdogan has had a typically shut and typically contentious relationship with Moscow — has expressed objections that might sluggish the method and require negotiations to handle its considerations.

“These two nations, particularly Sweden, they’re an entire hotbed of terrorism,” Mr. Erdogan mentioned on Thursday, an obvious reference to what the Turkish chief contends is their tacit help for Kurdish separatists.

Secretary of State Antony J. Blinken met his Turkish counterpart in New York on Wednesday, and Finnish officers mentioned they have been in talks with Turkey as nicely. Talking to reporters on Wednesday, Jake Sullivan, Mr. Biden’s nationwide safety adviser, expressed confidence that “Turkey’s considerations may be addressed” and that Finland and Sweden would in the end be capable to be a part of the alliance.

However Mr. Erdogan is famously unpredictable, and he may simply make the most of his leverage as a possible spoiler to press for his personal calls for, together with a lifting of sanctions on his nation for its buy of Russian-made antiaircraft methods.

Jens Stoltenberg, NATO’s secretary basic, mentioned on Thursday that he anticipated to resolve Turkey’s considerations.

“I’m assured that we are going to come to a fast choice to welcome each Sweden and Finland to hitch the NATO household,” he mentioned, including, “We’re addressing the considerations that Turkey has expressed.”

Mr. Erdogan’s calls for apart, the ceremony on the White Home was a exceptional second within the historical past of the Western alliance — a uncommon occasion in historical past the place a single occasion, Russia’s invasion, modified sentiment, and possibly NATO’s borders, virtually in a single day.

Underneath an settlement with the Soviet Union, Finland stayed exterior the alliance, which was created to comprise Russia after World Conflict II. It remained unbiased within the post-Soviet period even after becoming a member of the European Union and rising ever nearer with the West. Till now, Sweden had stored to greater than 200 years of neutrality.

However that posture has been rapidly deserted after Mr. Putin’s choice in February to invade Ukraine, which isn’t a NATO member. Each Finland and Sweden immediately realized that the menace from Russia had modified and that their standing as a bystander to great-power battle was now an enormous threat.

The pace of the reversal has been so nice that there was nearly not one of the debate that happened after the autumn of the Berlin Wall in 1989, when even a few of Washington’s most skilled Chilly Conflict diplomats warned that the extra Russia felt encircled, the upper the possibilities that it’d ultimately lash out, particularly if the hassle to combine the nation with the West failed.

On Wednesday, Mr. Sullivan mentioned that Mr. Biden had requested his nationwide safety officers whether or not they backed the addition of Finland and Sweden to the alliance and that that they had “emphatically supported” the transfer in a unanimous style.

The Rose Backyard ceremony intentionally contained echoes of a state go to, full with a army band. Mr. Biden characterised the transfer to usher Finland and Sweden into the alliance as virtually a formality, noting that each nations had contributed forces to conflicts in Kosovo, Afghanistan and Iraq — the foremost NATO commitments of the previous 20 years — and that they have been sturdy democracies that “meet each NATO requirement after which some.”

Mr. Biden argued that the 2 nations would add to the alliance’s firepower.

Finland has a complicated army that runs advanced operations to trace Russian exercise within the seas of Northern Europe and spends closely on trendy tools. Sweden is a tougher case: It dismantled a few of its army energy and, as Ms. Andersson conceded, must reorient its price range to spend 2 p.c of gross home product on protection, the goal for NATO members.

However for the USA, the first utility of getting the Nordic nations be a part of the alliance is the message despatched to Mr. Putin. In December, the Russian president demanded that the USA and NATO signal a treaty that may withdraw forces from former Soviet states and that they limit coaching actions and the position of arms.

As an alternative, NATO’s border with Russia would now prolong one other 810 miles, and the alliance’s expanded capabilities would complicate Russia’s defenses.

Mr. Putin’s anticipated response is the topic of hypothesis and planning periods. The Russian chief and his aides have thus far responded calmly, calling the transfer a mistake and saying they might react if weapons have been positioned near Russia’s borders.

However Finland and Sweden now see Mr. Putin as a far better menace to their safety than Soviet leaders have been through the Chilly Conflict. For Mr. Biden, the change in sentiment within the two nations is a chance to essentially fortify the trans-Atlantic alliance and weaken Russia whereas Mr. Putin stays in energy.

Mr. Biden alluded to that aim — which he has not absolutely articulated — in his feedback on the White Home on Thursday. “Lately, doubts started to come up,” he mentioned. “Was NATO nonetheless related?”

He mentioned that the Russia invasion proved it remained “the indispensable alliance for the world we face in the present day” and that the selections made by Sweden and Finland to decide on sides have been “testomony to that dedication.”

“Finland and Sweden make NATO stronger,” he mentioned, “not simply due to their capability however as a result of they’re sturdy, sturdy democracies.”

Earlier than the go to by Mr. Niinisto and Ms. Andersson, Mr. Biden additionally issued an announcement providing an off-the-cuff safety assure to the 2 nations whereas they look forward to formal membership within the alliance. That was meant to pre-empt any effort by Russia to intimidate the nations — maybe with cyberattacks, maybe with air or sea workout routines — whereas they’re awaiting membership, and the formal protections that go along with it.

However Mr. Niinisto alluded to the significance of pace. “Now that we’ve taken this primary decisive step, it’s time for NATO allies to weigh in,” he mentioned. “We hope for sturdy help from all allies and for a swift ratification of our membership as soon as it’s agreed.”

He referred on to Turkey, saying that “we are going to decide to Turkey’s safety, simply as Turkey will decide to our safety,” and including, “We take terrorism significantly.” That appeared to be an allusion to the Turkish concern concerning the Kurdish militants.

Ms. Andersson, turning to Mr. Biden and noting to laughter that “Swedes first set foot in your house state of Delaware in 1638,” mentioned the invasion of Ukraine “reminds us of the darkest days of European historical past.” It was “a watershed second for Sweden,” she mentioned, that compelled Swedes to rethink the essence of their safety.