US President Joe Biden signed a decree to impose new sanctions against Russia due to the actions of its government and special services against the sovereignty and interests of the country, a message on the website of the White House says.
I, JOSEPH R. BIDEN JR., President of the United States of America, find that specified harmful foreign activities of the Government of the Russian Federation […] constitute an unusual and extraordinary threat to the national security, foreign policy, and economy of the United States. I hereby declare a national emergency to deal with that threat.
As for Russia's "destabilizing" actions in the international arena, the Biden administration referred to: