People have a closer look at tanks at an exhibition at the museum in Kirovsk, Russia, on Sunday. AP

Ukraine’s supporters pledged billions of dollars in military aid to Ukraine on Friday, though the new commitments were overshadowed by defence leaders failing at an international meeting in the Ramstein air base in Germany, to agree on Ukraine’s urgent request for German-made Leopard 2 battle tanks.

State Duma Chairman Vyacheslav Volodin said that governments giving more powerful weapons to Ukraine could cause a “global tragedy that would destroy their countries.”

“Supplies of offensive weapons to the Kyiv regime would lead to a global catastrophe,” he said.

“If Washington and Nato supply weapons that would be used for striking peaceful cities and making attempts to seize our territory as they threaten to do, it would trigger a retaliation with more powerful weapons.”

Germany is one of the main donors of weapons to Ukraine, and it ordered a review of its Leopard 2 stocks in preparation for a possible green light. Nonetheless, the government in Berlin has shown caution at each step of increasing its commitments to Ukraine, a hesitancy seen as rooted in its history and political culture.

France and Germany committed to show “unwavering support” to Ukraine during ceremonies and talks on Sunday celebrating the 60th anniversary of their post-World War II friendship treaty. In a joint declaration, the countries said they would “stand with Ukraine for as long as it takes.”

Germany’s tentativeness has drawn heavy criticism, particularly from Poland and the Baltic states, countries on Nato’s eastern flank controlled by Moscow in the past and which feel especially threatened by Russia’s renewed imperial ambitions.

Polish Prime Minister Mateusz Morawiecki said that if Germany does not consent to transferring Leopard tanks to Ukraine, his country was prepared to build a “smaller coalition” of countries that would send theirs anyway.

“Almost a year had passed since the outbreak of war,” Morawiecki said in an interview with Polish state news agency PAP published Sunday.

In Washington, two leading lawmakers urged the US on Sunday to send some of its Abrams tanks to Ukraine, in the interests of overcoming Germany’s reluctance to share its own, more suitable Leopard 2 tanks.

“If we announced we were giving an Abrams tank, just one, that would unleash” the flow of tanks from Germany, Rep. Michael McCaul, the Republican chairman of the House Foreign Affairs Committee, told ABC’s “This Week on Sunday.” “What I hear is that Germany’s waiting on us to take the lead.”

Dmitry Medvedev, the deputy head of the Russian Security Council, said the meeting in Ramstein “left no doubt that our enemies will try to exhaust or better destroy us,” adding that “they have enough weapons” to achieve the purpose.

Medvedev, a former Russian president, warned on his messaging app channel that Russia could seek to form a military alliance with foes of the United States. He didn’t name the nations he had in mind, but Russia has defense cooperation with Iran and Venezuela, an existing military alliance with Belarus and strong ties with North Korea.. Since invading Ukraine, Russia also has increased both the scope and the number of its joint military drills with China.

“In case of a protracted conflict, a new military alliance will emerge that will include the nations that are fed up with the Americans and a pack of their castrated dogs,” Medvedev said.

Ukraine’s President Volodymyr Zelensky, who on Saturday mourned the victims of the helicopter crash, vowed on Sunday that Ukraine would prevail in the war.

“We are united because we are strong. We are strong because we are united,” the Ukrainian leader said in a video address as he marked Ukraine Unity Day, which commemorates the day in 1919 when East and West Ukraine were united.

Ukraine is asking for more weapons as it anticipates Russia’s forces launching a new offensive in the spring.

Associated Press