Four weeks ago, Germany agreed to send dozens of anti-aircraft tanks to help defend Ukraine from Russia's invasion, part of what it called a turning-point after decades of military restraint. Berlin says it can deliver the first Gepard tanks in July.

That's too slow, a Ukrainian parliamentarian said on Tuesday, as Russian forces launched an assault on the country's east.

"For us, July is like, 'what?'" Anastasia Radina, a member of the Ukrainian parliament, said at the World Economic Forum. "Let me put it like this: Let's ask a mother who is forced to sit in a basement with her newborn child who has no baby formula. ... How far from now is July for her?"