Statement from Press Secretary Jen Psaki on Russian Aggression Towards Ukraine
President Biden has been clear with the Russian President: If any Russian military forces move across the Ukrainian border, that's a renewed invasion, and it will be met with a swift, severe, and united response from the United States and our Allies. President Biden also knows from long experience that the Russians have an extensive playbook of aggression short of military action, including cyberattacks and paramilitary tactics. And he affirmed today that those acts of Russian aggression will be met with a decisive, reciprocal, and united response.
Jen Psaki, Statement from Press Secretary Jen Psaki on Russian Aggression Towards Ukraine Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/354163