"As we said when the Duma first made its request: this decision represents a complete rejection of Russia’s commitments under the Minsk agreements, directly contradicts Russia’s claimed commitment to diplomacy, and is a clear attack on Ukraine’s sovereignty and territorial integrity," Blinken said in a statement.

He said: "States have an obligation not to recognize a new 'state' created through the threat or use of force, as well as an obligation not to disrupt another state’s borders.  Russia’s decision is yet another example of President Putin’s flagrant disrespect for international law and norms."

Blinken said: "President Biden will sign an Executive Order that will prohibit all new investment, trade, and financing by U.S. persons to, from, or in the so-called 'Donetsk and Luhansk People’s Republics' regions of Ukraine."

"We will continue to coordinate with Ukraine and our Allies and partners to take appropriate steps in response to this unprovoked and unacceptable action by Russia," he said.

"Our support for Ukraine’s sovereignty and territorial integrity as well as for the government and people of Ukraine is unwavering.  We stand with our Ukrainian partners in strongly condemning President Putin’s announcement," he said.

Russian President Vladimir Putin has recognised the independence of two rebel-held breakaway eastern Ukrainian regions, amid escalating tensions between Russia and Ukraine with a Russian troop build-up near the two nations' borders spurring fears that Moscow could launch an invasion.

After delivering an hour-long speech in a ceremony carried on state television, Putin on Monday signed decrees recognising two seperatist regions of eastern Ukraine — Donetsk People's Republic and the Luhansk People's Republic.

Putin directed his parliament to recognise the separatist eastern Ukrainian regions and ratify treaties of friendship, following a meeting of the presidential Security Council.

"I consider it necessary to make a long overdue decision- to immediately recognize the independence and sovereignty of the Donetsk People's Republic and the Luhansk People's Republic," Putin announced.