BRUSSELS — Ukraine is redoubling its pleas for more advanced weapons like tanks and air defense missiles in a pivotal week of diplomacy involving its American and European allies, as they debate how best to help Kyiv’s forces take the battlefield initiative ahead of an expected new Russian offensive.
Ukraine’s new push began in earnest on Tuesday, when General Mark A. Milley, chairman of the U.S. Joint Chiefs of Staff, held his first face-to-face meeting with his Ukrainian counterpart, in Poland, nearly 11 months after the Russian invasion. And in Davos, Switzerland, Ukrainian officials and Olena Zelenska, wife of President Volodymyr Zelensky of Ukraine, attended the World Economic Forum to lobby global leaders and opinion makers to use their influence to help their country.
On Wednesday and Thursday, NATO defense ministers will meet in Brussels to take stock of the fight to help Ukraine, and on Friday, they will be joined at the Ramstein Air Base in Germany by officials of a broader group of nations that has coordinated aid to Ukraine. The U.S. defense secretary, Lloyd J. Austin III, will lead those discussions, focusing on the types and amounts of weaponry to supply, including the crucial question of whether to send Western tanks.
There is a growing consensus among Kyiv’s main Western supporters that time is wasting to enable the Ukrainian military to break the bloody, brutal deadlock with Russian forces in the east and south and drive them back, while also defending against Russian missile attacks that have devastated much of Ukraine’s infrastructure.
In Washington on Tuesday, the Dutch prime minister, Mark Rutte, told President Biden that the Netherlands planned to offer Ukraine a Patriot air defense missile battery, following the lead of the United States and Germany. In his nightly address, Mr. Zelensky called it “very important news.”
The U.S. goal in all its actions, Secretary of State Antony J. Blinken said on Tuesday, is “to put Ukraine in the strongest possible position when a negotiating table emerges so that there can be a just and durable peace.”
The Russians, too, are racing to rearm, re-equip and strengthen their own forces in the eastern Donbas region of Ukraine for their own expected spring or late winter push to grab more Ukrainian territory. President Vladimir V. Putin of Russia, who in September ordered the conscription of 300,000 men, said in televised remarks on Tuesday that some Russian arms factories were “working in several shifts and even around the clock.”
Western officials and military analysts say the war is about to reach a critical phase, with each side determined to seize strategic advantage. Russia’s invasion stalled after several months, and Ukraine’s counterattacks starting in September have also bogged down.
Though both sides in the war hope to go back on the offensive, the fighting has badly depleted their stocks of tanks and lighter armored vehicles, which are essential to rapid movement on the battlefield. In addition, the Ukrainians are low on ammunition for their vehicles, which are of Russian or Soviet design and are incompatible with Western munitions.
Germany is a key focus of allied discussions, because its Leopard 2 tanks are considered excellent and are numerous in European armies. Other countries have said they want to send some of their Leopards to Ukraine, but can do so only with Berlin’s permission. Olaf Scholz, the German chancellor, has so far not agreed to supply Ukraine with these advanced tanks, or to allow third countries to send theirs.
Britain announced on Monday that it would send 14 of its Challenger 2 tanks, which would be the first Western tanks in Ukraine’s forces. That move could make Mr. Scholz’s resistance to allowing other countries to export Leopards untenable, according to a senior NATO official. The British have been explicit about hoping to encourage other Western countries to follow suit by supplying modern tanks to Ukraine.
The argument over German tanks is likely to be resolved at the Ramstein meeting, where decisions will have more of a collective character. Mr. Scholz is likely to want vocal American support and participation in any decision he makes to provide German-made tanks or to allow other countries, including Poland and Finland, to do so, analysts say. Polls indicate that Germans support Ukraine but are not enthusiastic about committing German tanks to fighting Moscow.
Mr. Scholz’s widely criticized defense minister, Christine Lambrecht, resigned this week, and Mr. Scholz named Boris Pistorius, another Social Democrat, to replace her. Mr. Austin, the U.S. defense secretary, plans to meet with Mr. Pistorius ahead of the Ramstein gathering.
But the decision on tanks is one that the chancellor will make. Mr. Scholz has been reluctant to “go it alone,” as he has said, or to break completely with Moscow.
His caution has been echoed to some degree in Washington, where President Biden has been slower to provide advanced weapons than the Ukrainians would like, and has refused to send warplanes and longer-range munitions. The president shows no sign of sending the main American battle tank, the Abrams, though military analysts say its particular maintenance and fuel needs would make it much less useful to Ukraine than the Leopard.
Even so, the United States and its allies have given Ukraine other weapons that were once treated as off-limits, like HIMARS rocket artillery and the Patriot, the most advanced American-made air defense system. France, the United States and Germany all recently agreed to send their own fighting vehicles — less powerful than tanks — for the first time.
“As this aggression has evolved, so, too, has our assistance to Ukraine,” Mr. Blinken said at a news conference at the State Department with James Cleverly, the British foreign secretary.
The Biden administration has said that it has not dissuaded any ally from sending tanks — it applauded the British package that includes Challengers — and analysts say the White House is being careful not to be seen as putting pressure on Berlin.
“These are fundamentally decisions for each country to make,” Mr. Blinken said.
But Mr. Scholz needs U.S. cover; Germany has already moved a long way from its traditional policy of not sending weapons to a country at war. But Mr. Scholz has also been criticized internationally for giving military aid to Ukraine reluctantly and rather late, said Jana Puglierin, Berlin director of the European Council on Foreign Relations.
Poland and Finland have said they would supply Leopard tanks but were still awaiting a German green light.
A small number of Western tanks will not alter the shape of the conflict, but several hundred could help Ukrainian troops push back the Russians from a larger swath of eastern Ukraine. Ukrainian officials have asked for 300 tanks and some 600 armored infantry vehicles.
Ukraine hopes to drive the Russians out of Ukraine altogether, including from Crimea and part of the Donbas — the territory that Russia and its proxy forces seized in 2014 and 2015, and that Russia illegally annexed last year — but Western diplomats are largely skeptical.
If Ukraine could drive the Russians back to pre-invasion lines, before Feb. 24 of last year, then some Western officials think that Mr. Zelensky would be more prepared for peace talks — if, of course, Vladimir V. Putin, Russia’s president, would agree. So far there is no sign of any Russian interest in serious negotiations, making Mr. Zelensky’s choices easier.
But Western military officials caution that it will take time to deliver the tanks, train the Ukrainians to use them and, as important, maintain them, and to arrange a consistent pathway for spare parts and maintenance.
But the tanks also represent an important psychological boost for Ukraine, which is suffering through a brutal winter and hopes to regain battlefield momentum.
In an address late Monday, Mr. Zelensky urged allies to “speed up decision-making” and said that Britain’s new aid, including the Challenger tanks and a package of other sophisticated military equipment, “was exactly what we need.”
Reporting was contributed by Erika Solomon, Eric Schmitt and Michael Crowley.