NATO foreign ministers will meet in Prague on Friday to discuss how they coordinate military aid to Ukraine.
In the second day of a two-day meeting, ministers will try to make progress in talks over a €100 billion ($108 billion) proposal by NATO Secretary General Jens Stoltenberg to transfer responsibility for coordinating aid from an informal, United States-led initiative to the formal structures of NATO itself.
So far, NATO member states have been coordinating military aid not through NATO itself, but through the US-led Ukraine Contact Group (UCG). NATO's position is that it is not a party to the conflict between Russia and Ukraine.
But the contact group's reliance on US coordination has European allies worried that it could falter if November's presidential election returns Donald Trump to the White House, because they doubt his willingness to support Ukraine's war effort.
In April, Stoltenberg refused to be drawn on whether his proposal had anything to do with the possible return of Trump. He said the point is to make military aid to Ukraine more stable and predictable.
Another open question is what conditions NATO countries should impose on how their weapons are used by Ukraine. Some supply arms without conditions, but others stipulate they must only be used against targets on Ukrainian territory.
Stoltenberg said on Thursday that allies should consider lifting restrictions on the striking of targets in Russia. He argued that fighting has recently moved closer to the border, making it easier for Russia to launch attacks from inside its own borders.
The Kremlin said on Thursday there would be "consequences" if such strikes were to occur.