"Our sky must become safe again," Zelensky said during a video conference with NATO defence ministers.

"It depends fully on your choice. Choice whether life is indeed equally valuable everywhere. Choice whether you have an equal attitude to all partners. Choice whether we indeed are allies," he said.

Casting a bleak picture of his forces' ability to hold off Russian attacks on the ground and from the air, Zelensky said Ukraine could not defend itself without Western support.

"It is obvious that now, while Russia has air advantage and can rely on its drone and rocket terror, our capabilities on the ground, unfortunately, are limited," he said.

Zelensky called a Saturday vote in the US House of Representatives on whether to unlock a long-delayed $61 billion military aid package a "vitally important decision".

The aid has been delayed since last year amid political infighting in the Republican Party.

Speaking after another week of Russian aerial barrages that killed and injured dozens across the country, the Ukrainian leader said Kyiv needed more air defence systems to protect Ukrainian cities and save lives.

"To defend, we need seven more 'Patriots' or similar air defence systems -- and it's a minimum number. They can save many lives and really change the situation" Zelensky told a meeting of the NATO-Ukraine Council.

He also stressed the urgency of getting hold of the much-needed arms.

"This year we can't wait for decisions to be made," he said.

Ukraine is reliant on Western, primarily US, military support to fend off the Russian invasion.

Western systems, such as longer-range rockets, have previously been credited with allowing Ukraine to match the better-supplied Russian troops.

But Kyiv has also complained that promised deliveries throughout the two-year war have often arrived too late or in too small numbers to have a decisive impact on the battlefield.