BRUSSELS — The European Union’s top officials said the bloc will impose more sanctions against those involved in Russia’s recognition of two separatist regions of eastern Ukraine amid fears of a potential Russian invasion of the country.

The announcement came after Russian President Vladimir Putin signed a decree to formally recognize the independence of two rebel-controlled regions in eastern Ukraine.

In a joint statement on Monday evening, EU Commission President Ursula von der Leyen and Council President Charles Michel said the recognition was “a blatant violation of international law.”

The pair added that the EU “will react with sanctions” and “reiterates its unwavering support to Ukraine’s independence, sovereignty and territorial integrity within its internationally recognised borders.”

The White House said President Biden will also order new sanctions, and called Putin's announcement a “blatant violation of Russia’s international commitments.”

The American sanctions will prohibit new investment, trade and financing in the two separatist regions of Ukraine recognized by Putin - the so-called Donetsk and Luhansk People's Republics.

There's been a chorus of condemnation from Western allies reacting to President Putin's Monday evening announcement.

British Foreign Secretary Liz Truss said "we will not allow Russia's violation of its international commitments to go unpunished"; while Ukraine's President Volodymyr Zelenskyy tweeted that he had already spoken to President Biden and planned to speak with British Prime Minister Boris Johnson about the situation as well.

Earlier, Johnson said plans to recognize the two breakaway republics were "a very ill omen and a very dark sign" and said the UK would have to now consider what more they could do to support Ukraine.

Finland's President Sauli Niinistö, one of the few European leaders to have a long-established working relationship with Vladimir Putin, also released a statement condemning his actions, calling it a "serious breach of the Minks agreements."

French President Emmanuel Macron condemned the Russian decision and called for an immediate UN Security Council meeting and “targeted European sanctions.”

The recognition of the rebel regions came as more than 150,000 Russian troops have surrounded Ukraine from three sides in what Western allies see as a sign of an imminent invasion.

American officials have warned that Moscow could try to create the pretext for attacking Ukraine with false-flag attacks in the volatile rebel east or other similar action.

Professor Sam Greene, Director of The King's Russia Institute at Kings College London says he believes President Putin has "laid the rhetorical groundwork for war, but didn't declare it."

"He laid the foundations for a formal military presence in [Donetsk and Luhansk People's Republic] but didn't define the borders. The practiced strategic ambiguity continues. We still don't know where this is going, and that's the point" he wrote on Twitter.

Ukrainians in the capital Kyiv, meanwhile, bristled at Putin's Monday evening announcement.

“Why should Russia recognize (the rebel-held regions)? If neighbors come to you and say, ‘This room will be ours,’ would you care about their opinion or not? It’s your flat, and it will be always your flat," said Maria Levchyshchyna, a 48-year-old painter in the Ukrainian capital. “Let them recognize whatever they want. But in my view, it can also provoke a war, because normal people will fight for their country.”

Russia says it wants Western guarantees that NATO won’t allow Ukraine and other former Soviet countries to join as members - and Putin said Monday that a simple moratorium on Ukraine’s accession wouldn’t be enough. Moscow has also demanded the alliance halt weapons deployments to Ukraine and roll back its forces from Eastern Europe - demands flatly rejected by the West. — Euronews