The U.S. ambassador to the United Nations warned that should the current plan fail in Syria, the world is facing a 'worst case scenario' of intensifying civil strife.

Ambassador Susan Rice told CNN's Wolf Blitzer that that there needs to be "maximum international pressure" on Syria's president by the United Nations Security Council "including sanctions and potentially other steps."

"Should all of that fail or not be possible because it perhaps would be vetoed again, then we're into a situation which is chaotic," Rice said in the interview that aired Wednesday on Situation Room with Wolf Blitzer.