The United States and its Western allies have announced plans to impose new sanctions against Russia after Moscow recognized two breakaway regions in eastern Ukraine as independent republics and sent "peacekeeping" forces there.
The White House said on Tuesday the United States will announce the first of what could be multiple levels of tough new sanctions and export controls against Russia later in the day.
"We think this is, yes, the beginning of an invasion, Russia's latest invasion of Ukraine," deputy national security adviser Jonathan Finer said on CNN. "For the third or fourth time, I am calling it an invasion. We are taking a severe response, including sanctions on Russia that we'll be rolling out in a matter of hours," he said.
After a UN Security Council meeting on Monday evening, US Ambassador to the United Nations Linda Thomas-Greenfield had also told reporters that Washington would announce its first sanctions on Russia on Tuesday.
"Tomorrow, the United States will impose sanctions on Russia for this clear violation of international law and Ukraine sovereignty and territorial integrity," she said. "We can, will, and must stand united in our calls for Russia to withdraw its forces, return to the diplomatic table and work toward peace."
Separately, EU foreign policy chief Josep Borrell said that the foreign ministers of the 27-nation bloc would make a decision on a European response on Tuesday.
"I have decided to convene an informal meeting of the Council of the European Union involving the foreign ministers here in Paris after the meeting on the Indo-Pacific region. The ministers will make a decision on a European response that will take the form of sanctions," he said.
Borrell added that sanctions would be coordinated with the US, Canada, and the UK. "I am sure that the decision on sanctions will be made unanimously."
Russian President Vladimir Putin on Monday signed a decree recognizing the breakaway Lugansk and Donetsk regions in eastern Ukraine as independent republics and instructed Russia's Defense Ministry to deploy peacekeeping troops to the two regions.
Donetsk and Lugansk regions were turned into self-proclaimed republics by its ethnic Russian residents in 2014, which triggered a violent conflict between government forces and the secessionists.
The conflict worsened following a wave of protests in Ukraine that led to the overthrow of a democratically-elected pro-Russia government, which was later replaced with a pro-West administration.
President Putin had earlier warned that the US was deliberately designing a scenario to lure Russia into a war over Ukraine.