The international row over whether Ukraine should be allowed to use Western weapons to strike targets on Russian soil will dominate this week’s meeting of Nato foreign ministers in Prague.
The Americans will arrive in the Czech capital under pressure to relax the rules on their donations, after a string of public easing of restrictions.
Jens Stoltenberg, Nato’s departing secretary-general, has launched a campaign to convince allies to change their minds.
His attempt is seen largely futile, given donations to Ukraine are managed bilaterally and not through the Western military alliance.
But a growing coalition, led by the Brits, French and Eastern Europeans, will work hard to convince their American counterparts that it is the right thing to do, given Russia is launching more attacks from its own soil.
Elsewhere, ministers will attempt to find ways to satisfy Ukraine given the war-torn country won’t be offered a clear pathway to membership, as reported by the Telegraph earlier this week.
Plans for a $100 billion war chest to bring Kyiv’s armed forces to Nato standard, presented by Mr Stoltenberg in March, have already run into difficulties, given some member states’ reluctance to give Nato greater involvement in weapons deliveries, amid fears it could drag the alliance into a wider war with Russia.