A poster reading "All to defend homeland" and "Donbass is our land" is pictured in a street. Denis Pushilin, head of the Donetsk People's Republic, asks Russian President Vladimir Putin to recognize independence of thA poster reading “All to defend homeland” and “Donbass is our land” is pictured in a street. Denis Pushilin, head of the Donetsk People’s Republic, asks Russian President Vladimir Putin to recognize independence of the Donetsk People’s Republic. As tension escalated in east Ukraine on 18 February, 2022, the Donetsk People’s Republic announced a mass evacuation of civilians to Russia. On 19 February 2022, it announced general mobilisation.

The White House said it was ready to respond to Putin's decision to recognize the independence of the two regions.

White House press secretary Jen Psaki said that Biden would sign an executive order that would prohibit new investment, trade, and financing by the U.S. to the Republic of Luhansk.

To be clear, these measures are separate from and would be in addition to the swift and severe economic measures we have been preparing in coordination with allies and partners.

Additional details of the Biden administration's actions will be shared by the Departments of State and Treasury.

In an hour-long televised address Monday evening, Putin decided to recognize the so-called "Donetsk People's Republic" and the "Luhansk People's Republic".

The U.S. and European allies warned that this kind of move by Putin could lead to a Russian invasion.

European leaders issued fresh threats to respond to Putin's violation of international law.

The European Union will impose sanctions against those involved in this illegal act. The European Commission President Ursula von der Leyen and European Council President CharlesMichel wrote a joint statement to reiterate the Union's support for the independence, sovereignty and territorial integrity of Ukraine.

The development was called a very dark sign by the U.K. Prime Minister Boris Johnson.

It's another sign that things are moving in the wrong direction. Boris said Monday evening that the U.K. will continue to fortify NATO's eastern flank.

NATO Secretary-General Jens Stoltenberg said Putin's announcement further undermines Ukraine's sovereignty and territorial integrity and erodes efforts towards a resolution of the conflict. He called on Moscow to reverse its military build-up on the borders of Ukraine.

A White House official told NBC News that Biden spoke to Zelenskyy for nearly 40 minutes. Biden spoke with the leaders of France and Germany after his call with the Ukrainian president.

The Secretary of State warned last week that a swift and firm response from the United States would follow the recognition of Luhansk.

This is breaking news. You can check back for updates.