The U.S. has been working with European allies to help Ukraine build its long-term force, efforts that would bring Kyiv closer to NATO. Individual members including the U.S. are working to reach bilateral agreements with Ukraine.

More than two years into the deadliest war in Europe since World War Two, Western allies are debating how to stop Russian military advances and Putin is increasingly evoking the risk of a global war.

Debate on strikes inside Russia

Discussions over whether to allow Kyiv to use Western-supplied arms to strike inside Russia appear to be gathering momentum and encroaching on the meeting.

Ukraine has been urging its supporters, particularly the United States, to permit the use of longer-range weaponry to target sites within Russia.

The U.S. and Germany have so far resisted, fearing such actions could draw them closer to direct conflict with Moscow.

Ahead of the NATO meeting, which begins with a dinner on Thursday, alliance chief Jens Stoltenberg emphasized the need for members to reconsider these restrictions, as they limit Kyiv's ability to defend itself.

French President Emmanuel Macron signaled a shift on Tuesday, stating that Ukraine should be allowed to “neutralize” bases in Russia used for launching strikes.

German Chancellor Olaf Scholz, however, was more cautious, asserting that Ukraine should act within the law and noting that Berlin had not supplied weapons intended for striking Russia.

In the United States, the White House maintained its opposition to Ukraine using American arms for strikes inside Russia, although Blinken hinted that this stance might change.

Meanwhile, Moscow responded strongly, with President Vladimir Putin warning of “serious consequences” if Western countries permit Ukraine to strike.

Advocates for giving Ukraine more leeway hope that momentum is building for the United States and others to change their positions, as Kyiv struggles to counter Russia’s offensive in the Kharkiv region.