"We strongly support bringing into NATO countries that seek to join and that can add to NATO's capabilities," US Secretary of State Antony Blinken told reporters.

On Zelensky's proposal to speed up membership, he said, "There's a process for doing that and countries will continue to follow that process."

Canadian Foreign Minister Melanie Joly, speaking with Blinken after talks in Washington, also voiced support for Ukraine's bid.

"We believe in NATO's open-door policy and we've always been in favor of Ukraine acceding to NATO," she said.

Under NATO rules, any decision to admit a new member needs to be unanimous. Hungary in the past has been particularly vocal against Ukraine but other European nations have also hesitated at bringing in a nation that is at war -- which, by treaty, would oblige the alliance to come to its defense.

Zelensky, in a video after President Vladimir Putin announced that Russia was annexing occupied Ukrainian territory, said that Kyiv had proven its compatability with NATO during the campaign against the invasion.

"We are taking a decisive step by signing Ukraine's application for accelerated accession to NATO," Zelensky said.