Ukrainian President Volodymr Zelensky has made a direct appeal for tanks at crunch talks involving dozens of Western allies in southern Germany.
The US and European nations have already promised more weapons.
But Mr Zelensky told defence ministers at Ramstein airbase: “Hundreds of thank yous are not hundreds of tanks.”
Germany in particular is under growing pressure to send its Leopard 2 tanks, and to allow other countries to provide Ukraine with their own Leopards.
As the nation of manufacture, it has to give its permission before countries such as Poland or Finland commit to re-exporting them.
Defence colleagues from more than 50 countries gathered at the airbase on Friday, a day after several nations pledged more equipment to help Ukraine fend off further Russia campaigns. US Defense Secretary Lloyd Austin told them it was time to “dig deeper”.
Almost 11 months into Russia’s war in Ukraine, Nato military figures believe Moscow is planning a renewed spring offensive with troop numbers bolstered by a partial mobilisation since the end of September.
Western officials believe there’s a “window of opportunity” in the coming weeks for Ukraine to push Russia forces back. They say Moscow is running short of ammunition and trained troops – despite efforts to replenish stocks and mobilise additional forces.
For its part, Russia has warned Western countries that providing tanks to its enemy would mark an “extremely dangerous” escalation in the conflict.
The UK has already announced it will send 14 Challenger 2 battle tanks. But Kyiv wants more tanks and UK Defence Secretary Ben Wallace said he hoped that the 50 allies would “all hear the message that unlocking the tank is part of 2023”.
Germany’s Leopard tanks are key to that equation. They’re in more plentiful supply than the British tank, and are operated by more than a dozen other nations.
Ahead of the Ramstein meeting Mr Zelensky criticised Germany’s hesitant attitude to sending tanks, assuring Berlin that the Leopards would only be used in self-defence and not go through Russia. “If you have Leopard [tanks], then give them to us,” he told German public TV.
Polish deputy foreign minister Pawel Jablonski indicated on Friday that Warsaw might be prepared to provide Ukraine with Leopards regardless of Berlin’s views. “We’ll see. I think if there is strong resistance, we’ll be ready to take even such non-standard action. But let’s not anticipate the facts,” he told Polish radio.
“Tanks for Ukraine are tanks for freedom,” Ukrainians defence ministry adviser Yuriy Sak told the BBC. If they were not sent, other countries might one day “have to use them themselves” against Moscow, he warned.
Berlin said this week that a decision on the Leopard was conditional on the US agreeing to send Abrams tanks, which it is not intending to do. But the new German defence minister, Boris Pistorius, said he was not aware of “such stipulation”.
There are fears of escalation in Berlin and of going it alone. Until recently Germany refused requests to send a Patriot air defence battery, but it relented as soon as the US did the same. On tanks too, Berlin would like to see the US take the lead.
Ben Wallace has rejected talk of escalation. Germany along with the US and UK, he argued, had already supplied artillery systems, like Himars, with a much longer range.
Mr Zelensky has repeatedly taken aim at Berlin’s perceived hesitancy and on Thursday criticised suggestions that the US and Germany were only planning to commit vehicles if the other nation did the same.
Retired US Army general David Petraeus said there was “legitimate reluctance” in Washington on the issue of sending Abrams tanks because it was difficult to maintain and had a jet turbine.
He told the BBC it was “imperative” that any Western tank donations were made “early enough, so [Ukrainian soldiers] can actually train on them”.
On Thursday, Western nations pledged to send more vehicles, artillery and munitions to bolster the Ukrainian war effort.
The US committed a new package worth $2.5bn (£2bn), saying this took its spend on Ukrainian support to $26.7bn since last February’s full-scale invasion by Russia.
Tanks were not included in the offer, but the Pentagon did promise an extra 59 Bradley armoured vehicles, 90 Stryker personnel carriers and Avenger air defence systems, among other provisions.
The announcement came after nine European nations promised more support of their own following a meeting in Estonia. This included:
- UK – 600 Brimstone missiles
- Denmark – 19 French-made Caesar self-propelled howitzers
- Estonia – howitzers, ammunition, support vehicles and anti-tank grenade launchers
- Latvia – Stinger air-defence systems, two helicopters, and drones
- Lithuania – anti-aircraft guns and two helicopters
- Poland – S-60 anti-aircraft guns with 70,000 pieces of ammunition
- Czech Republic – produce further large calibre ammunition, howitzers and APCs
- Netherlands – support expected to be detailed on Friday