Ukraine’s President Volodymyr Zelensky said on Friday Kyiv is requesting fast-track NATO membership after Russia formally annexed four Moscow-held regions of Ukraine.

The Ukrainian leader’s comments come soon after Russian President Vladimir Putin held a ceremony in Moscow to proclaim four partially occupied Ukrainian regions as annexed Russian land.

The video showed Zelensky announcing the decision and then signing a document flanked by his prime minister and the speaker of parliament.

“We have already proven our compatibility with Alliance standards… We are taking a decisive step by signing Ukraine’s application for accelerated accession to NATO,” Zelensky said in a video posted by the Ukrainian presidency on social media.

Zelensky also warned that he would not negotiate with Russia as long as President Vladimir Putin is in power. “Ukraine will not hold any negotiations with Russia as long as Putin is the president of the Russian Federation. We will negotiate with the new president,” Zelensky said.

Putin signed treaties to annex parts of Ukraine in defiance of international law, vowing to protect the newly incorporated regions by “all available means” in another escalation of his seven-month invasion of the country.

Putin urged Ukraine to sit down for peace talks but immediately insisted he won’t discuss handing back occupied regions — keeping him on a collision course with the Ukrainian government and its Western backers that have rejected his land-grab.

In a Kremlin ceremony at the ornate St. George’s Hall to herald the annexation of the occupied parts of Ukraine, Putin accused the West of fueling the hostilities as part of what he said is a plan to turn Russia into a “colony” and a “crowds of slaves.” The hardening of his position, in the conflict that has killed and wounded tens of thousands of people, further cranked up tensions, already at levels unseen since the Cold War.

The European Union immediately responded to Putin’s latest step with a joint statement rejecting and condemning “the illegal annexation” of the four regions: Donetsk, Luhansk, Kherson and Zaporizhzhia.

(With inputs from agencies)