Washington — President Biden on Monday urged Americans to remain calm as scientists work to determine the strength and the transmissibility of the new Omicron variant of the coronavirus, saying the U.S. has the ability to deal with the new strain that is circulating the globe.

The president, flanked by chief medical adviser Dr. Anthony Fauci and Vice President Kamala Harris, told the nation the variant is a “cause for concern, not a cause for panic.” He said the U.S. has more tools to fight COVID-19 than ever before, and is in a much better position to fight the virus than it was in March 2020, or even December 2020. The president said he’ll release a more detailed strategy on Thursday for fighting COVID-19 and the Omicron variant in the weeks ahead. 

“Sooner or later, we’re going to see cases of this new variant here in the United States,” he said. “We’ll have to face this new threat, just as we faced those that have come before it.”

The Biden administration imposed travel restrictions on those coming from eight countries in Southern Africa beginning Monday. Mr. Biden said the restrictions are necessary to give Americans more time to prepare for the variant by getting the vaccine or a booster shot. 

“While we have the travel restrictions can slow the speed of Omicron, it cannot prevent it,” the president said. “But here’s what it does: it gives us time. It gives us time to take more actions; to move quicker — to make sure people understand you have to get your vaccine, you have to get the shot, you have to get the booster.”

The president urged those 18 and older who are at least six months out from their second vaccine shot to get the booster. 

“If you’re 18 years or over and got fully vaccinated before June the first, go get the booster shot today,” the president pleaded. He also encouraged people to wear masks in crowded indoor places, while saying a return to stringent lockdowns is off the table.

Mr. Biden’s remarks on the U.S. response to the Omicron variant follow a meeting the president held with his COVID-19 Response Team upon his arrival at the White House on Sunday. They met again Monday morning. 

The World Health Organization deemed Omicron a “variant of concern” last week after South Africa reported the new strain November 24. Its discovery sent countries scrambling to mitigate the spread of the variant, and the Biden administration rolled out restrictions on air travel from eight nations in southern Africa, which go into effect Monday.

In addition to South Africa, the Omicron variant has been detected in at least 14 countries. The Centers for Disease Control and Prevention said Friday that no cases of the new strain have been identified in the U.S. so far, but Dr. Scott Gottlieb, former head of the Food and Drug Administration, predicted Sunday in an interview with CBS News’ “Face the Nation” that the Omicron variant is “almost definitely” here already.

Researchers in South Africa and around the world are working to determine whether the Omicron variant is more transmissible than other coronavirus strains, including the Delta variant, as well as whether it causes more severe disease than other variants. The World Health Organization said it is also working with partners to understand the impact of the Omicron variant on the effectiveness of vaccines. 

Fauci told “CBS Mornings” that it will take “maybe a couple of weeks” to get more data about the variant’s transmissibility and severity. He said South African scientists report that the variant “appears to be spreading very readily” but it remains unclear whether those infected with Omicron develop more severe symptoms than those infected with other coronavirus strains.