BRUSSELS — NATO introduced a doubling of its navy presence close to Ukraine on Wednesday and stated the alliance would assist the nation put together for potential chemical, organic and even nuclear threats from the Russian invaders, which might be a once-unthinkable enlargement within the month-old battle.

The announcement by Jens Stoltenberg, NATO’s secretary common, got here hours earlier than President Biden landed in Europe for a rare technique session with the alliance, created in 1949 to include the Soviet Union. The warnings underscored the urgency of efforts to stop the battle from spreading past Ukraine’s borders and entangling NATO in a direct battle with Russia.

The chance that Russia may resort to weapons of mass destruction additionally mirrored the Russian navy’s failure — even with the usage of indiscriminate weapons aimed toward terrorizing civilians — to attain greater than a stalemate to this point within the face of an unexpectedly tenacious Ukrainian resistance.

Mr. Biden’s NATO assembly on Thursday will likely be adopted by a session with counterparts from the Group of seven industrialized powers, after which with the European Union. The final will embody an look by President Volodymyr Zelensky of Ukraine, by way of video hyperlink from an embattled Kyiv. That dialogue is predicted to discover methods to additional tighten the already-severe Western financial sanctions on Russia which might be aimed toward pressuring its president, Vladimir V. Putin, into halting the battle.

These punishments, which have crashed the ruble’s worth and begun to trigger extreme shortages inside Russia, have erased many years of its monetary integration with the world within the area of some weeks. Russia’s determination to strictly management how the Ukraine battle is reported domestically — it’s a felony offense to name the battle a battle or invasion — has additional raised repression within the nation.

Mr. Biden desires to metal the allies for the chance that the battle lasts for months or years, requiring a long-term dedication to financial and navy confrontation, administration officers say.

However the Europeans are unwilling to comply with the USA in stopping purchases of Russian oil and fuel, that are far more crucial to their economies. Chancellor Olaf Scholz of Germany stated such a halt would imperil “a whole bunch of 1000’s of jobs.”

So, in some methods, Mr. Biden’s back-to-back conferences additionally signify essentially the most extreme check of the trans-Atlantic alliance’s cohesion over the Ukraine disaster.

The alliance has to this point proved remarkably unified in making an attempt to show Russia right into a pariah and assist Ukraine’s outgunned protection forces to frustrate the Russian navy’s floor advances within the nation.

And Russia might have incurred extra losses than beforehand thought, in keeping with a senior NATO navy official who, talking on the situation of anonymity on Wednesday, stated that 7,000 to fifteen,000 Russian troops had been killed in Ukraine over the previous month. The higher vary is greater than double the Pentagon’s determine of round 7,000.

New indicators of pressure throughout the Kremlin hierarchy surfaced Wednesday as effectively. Bloomberg reported that Russia’s local weather envoy, Anatoly Chubais, had left the nation, “citing his opposition” to the battle. The Russian state information company TASS stated solely that Mr. Chubais, a former deputy prime minister beneath Boris N. Yeltsin, the previous Russian president within the Nineties, had stepped down.

If something, Russia’s diplomatic isolation appeared to deepen on Wednesday. Poland expelled 45 Russian diplomats, accusing them of spying. On the United Nations, a Normal Meeting decision condemning Russia for inflicting a humanitarian catastrophe appeared on its strategy to a lopsided approval, as a result of it’s a discussion board during which Moscow doesn’t maintain a veto.

And a humanitarian decision proposed by Russia on the Safety Council — the place it will probably veto any decision — made no point out of Russia’s navy assaults in Ukraine, prompting criticism that verged on ridicule. The measure failed with solely Russia and China voting in favor, and 13 abstentions. (A decision wants 9 sure votes and no vetoes.)

Regardless of Russia’s frustration in Ukraine to this point, Mr. Putin has proven no signal of backing down in his marketing campaign to subjugate the previous Soviet republic with bombings and shellings which have leveled all or components of some cities, displaced 1 / 4 of the inhabitants and created the most important refugee disaster in Europe since World Conflict II.

Mr. Biden and different Western leaders have denounced Mr. Putin’s willingness to order such ways, and Mr. Biden has gone as far as to name his Russian counterpart a battle felony — an outline that outraged the Kremlin. On Wednesday, Secretary of State Antony J. Blinken, who was becoming a member of Mr. Biden in Europe, took his remarks one step additional, saying that the USA has formally concluded that Russian forces dedicated battle crimes in Ukraine.

The sensible implications of Mr. Blinken’s announcement weren’t instantly clear. However they appeared certain to additional worsen the American relationship with Russia, already at its most fragile stage for the reason that Chilly Conflict.

Extra proof of Russia’s willingness to focus on Ukrainian civilians got here Wednesday with the primary identified use of Grad rocket launchers to strike Kyiv, the capital, which Russian forces have sought to encircle for the reason that battle’s early days. A hail of Grad rockets slammed right into a residential space close to the middle of Kyiv, setting off a burst of explosions that prompted in depth harm to houses.

Reflecting heightened considerations about Mr. Putin’s plans, Mr. Stoltenberg stated NATO was doubling its battle teams to eight alongside its jap frontier. He stated the extra 4 combat-ready, battalion-size items, which usually have a number of hundred troops every, have been deploying in Bulgaria, Hungary, Romania and Slovakia.

“All of that is the speedy response to the Russian invasion of Ukraine,” Mr. Stoltenberg stated, including that the forces would stay there “so long as crucial.”

He additionally warned that the usage of chemical or organic weapons may straight impression NATO members neighboring Ukraine. “Chemical weapons could have devastating penalties for Ukraine, however they may even have extreme penalties for neighboring international locations due to the contamination or unfold of chemical brokers or organic brokers,” Mr. Stoltenberg stated.

And Mr. Stoltenberg stated that NATO allies on Thursday would supply Ukraine assist to mitigate such an assault. “Tomorrow, I anticipate allies will agree to offer further assist, together with cybersecurity help, in addition to gear to assist Ukraine shield towards chemical, organic, and radiological and nuclear threats,” he stated, declining to specify what that gear may be.

In one other signal that Western allies now contemplate the usage of weapons of mass destruction by Russia an actual chance, European officers stated that the bloc was, alongside the USA, Britain and Canada, engaged on a brand new package deal of sanctions that may take impact ought to Mr. Putin resolve to make use of chemical or organic weapons in Ukraine.

The financial fallout from the battle and the sanctions is extra acute for Europeans than for People. Although Russia will not be a serious participant on the earth financial system, it’s a main exporter of oil, fuel, coal, and important metals which might be utilized in every little thing from cell phones to vehicles. Russia is also a number one exporter of wheat and corn.

The persistent uncertainty mixed with worries about shortages have additional jacked up costs that have been already inflated by the coronavirus pandemic and supply-chain chokeholds.

The European Union, on common, will get 40 p.c of its pure fuel and 1 / 4 of its oil from Russia. Some particular person nations are far more dependent.

Germany, which has the biggest financial system in Europe, will get 55 p.c of its pure fuel, greater than a 3rd of its oil, and over half of its coal from Russia. Robert Habeck, the nation’s financial and local weather minister, has warned that a direct halt to Russian power provides may trigger “mass unemployment, poverty, individuals who can’t warmth their houses, individuals who run out of petrol.”

Vitality provides have been exempted from the European sanctions imposed on Russia to this point on the insistence of European governments. Within the meantime, the European Union has agreed to maneuver aggressively to cut back imports of Russian pure fuel by two-thirds by subsequent winter and eradicate them by 2027.

Mr. Putin appeared to have additional difficult Europe’s dependence on Russian power by saying on Wednesday that “unfriendly international locations” like members of the European Union and Britain should pay for his or her fuel with rubles — as an alternative of {dollars} or euros. That requirement would assist strengthen the ruble’s worth — exactly the other of what the West meant.

“Russia’s demand was a gambit to drive Europe right into a Hobbesian alternative between destroying the ruble’s worth and persevering with to obtain Russian oil,” stated Robert McNally, a former power adviser to President George W. Bush.

Matina Stevis-Gridneff and David E. Sanger reported from Brussels, and Rick Gladstone from New York. Reporting was contributed by Carlotta Gall from Kyiv, Patricia Cohen from London, Christopher F. Schuetze from Berlin, Michael D. Shear from Brussels, Michael Crowley from Washington, Anton Troianovski from Istanbul, Farnaz Fassihi from New York, and Clifford Krauss from Houston.