US Defense Secretary Lloyd Austin urged allies on Friday to dig deeper to support Ukraine at the start of a meeting of dozens of defence ministers at an air base in Germany, as pressure piled up on Berlin to provide tanks to Kyiv.
NATO and defence leaders from roughly 50 countries are meeting at Ramstein Air Base, the latest in a series of arms-pledging conferences since Russia invaded Ukraine nearly 11 months ago.
"Russia is regrouping, recruiting, and trying to re-equip," Austin said at the start of the meeting.
"This is not a moment to slow down. It's a time to dig deeper. The Ukrainian people are watching us," he said without making specific reference to tanks.
The United States announced an additional $2.5 billion in military aid for Ukraine on Thursday, a package which will include more armoured vehicles and ammunition.
Finland announced a new donation of more than 400 million euros ($434 million) worth of defence equipment for Ukraine, not including German-made Leopard 2 heavy tanks which it said it could also send if there is an agreement with allies.
Berlin has veto power over any decision to export the Leopard tanks, fielded by NATO-allied armies across Europe and seen by defence experts as the most suitable for Ukraine.
The Kremlin's spokesman said on Friday that Western countries supplying additional tanks to Ukraine would not change the course of the conflict and that they would add to the problems of the Ukrainian people.