Americans should be prepared to fight the spread of the new COVID-19 variant Omicron, but it is too soon to say what actions are needed, including possible mandates or lockdowns, top U.S. infectious disease official Dr. Anthony Fauci said on Sunday.

The United States must do "anything and everything" amid likely cases of the variant, but it is "too early to say" whether we need new lockdowns or mandates, Fauci told ABC News.

"You want to be prepared to do anything and everything," he added.

The new Omicron coronavirus variant, first discovered in South Africa and announced in recent days, has now been detected in a growing number of other countries. 

Fauci, in an NBC News interview on Saturday, said it was possible that it was already in the United States, although no official case has been confirmed.

U.S. health officials will be speaking again with their South African colleagues about the variant later on Sunday, he told ABC News' "This Week" program in a separate interview.