"NATO as an alliance, as an institution, is completely sidelined and doing literally nothing. I'm sorry to say it," Kuleba told the World Economic Forum in Davos.

But he praised Brussels for its "revolutionary, groundbreaking decisions, which even they themselves did not expect to make".

When Russia launched its massive attack on February 24, there was a widespread sense among the Ukrainian public that it would be NATO, not the EU, that would rush to help the country.

"At the beginning of the war, there was a public sentiment that NATO was the strong force and the EU was only capable of expressing various different levels of concern," the foreign minister said.

"But war is always a test that takes the masks off."

He did, however, qualify his remarks, saying some "NATO allies are helping us."

Kyiv has long complained about a lack of clarity from NATO about joining the military alliance. It is a move which Russia has vigorously opposed.

The EU has imposed a barrage of sanctions against Moscow since its attack, and even hopes to reach an agreement on an oil embargo on Russia.