President Joe Biden on Monday told Americans not to "panic" over the newly identified Covid variant Omicron and said he does not foresee new lockdowns or extending travel restrictions for now.

The virus variant, first detected in South Africa but already appearing in multiple countries, "is a cause for concern, not a cause for panic," Biden said.

He stressed that the United States was in a good position to control Omicron's spread without having to resort to lockdowns or more travel bans beyond restrictions already imposed on eight southern African countries.

"We have more tools today to fight the variant than we've ever had before," he said, adding that his chief medical advisor Anthony Fauci expects current vaccines to work against the new variant, with boosters enhancing protection.

"We'll fight this variant with scientific and knowledgeable actions and speed, not chaos and confusion," Biden said in nationally televised remarks from the White House, flanked by Fauci and Vice President Kamala Harris.

Biden promised a "detailed strategy" for the fight against Covid-19 this winter but signaled that Americans will not be subjected to burdensome measures.

"Not with shutdowns or lockdowns, but with more widespread vaccinations, boosters, testing, and more," he said, specifying that he does not see a need now for ordering vaccine or testing mandates on domestic air travel.

The United States, Canada and the European Union have all severely restricted entry of travelers from South Africa and seven other countries in the region. However, Biden also said "I don't anticipate" more travel bans.

"The degree of the spread impacts on whether or not there's a need for any travel restrictions," he said.