Originally Published: 29 NOV 21 19:24 ET

By Maegan Vazquez, CNN

(CNN) -- Dr. Anthony Fauci, the nation's top infectious diseases expert, said Monday that he doesn't anticipate the United States will implement additional travel restrictions even if the Omicron variant proves worse than previous strains of Covid-19.

President Joe Biden announced last week that the US would restrict travel from South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi in response to the new and potentially more transmissible coronavirus variant first identified by South African scientists. Several other nations have followed suit in restricting travel from southern Africa nations.

Asked by CNN's Jake Tapper on Monday whether he expects more travel restrictions should Omicron prove to be more contagious and deadly, Fauci, Biden's chief medical adviser, replied, "I don't think so, Jake."

"I think what was done about the restrictions from South Africa and neighboring countries was merely because when the information came out about the molecular makeup of this virus with all of the mutations that were of concern, we felt that we needed to do something right away," Fauci, the long-time director of the National Institute of Allergy and Infectious Diseases, told Tapper on "The Lead."

"Hopefully those restrictions are not going to be a very long duration until we get a handle as to what's going on. But we do not anticipate any further restrictions," he added.

Fauci also said that the travel restrictions are not going to have much of an impact "in the big picture of whether (the Omicron variant) gets here or not."

"But ... it will provide us maybe a couple of weeks of getting better prepared," he added.

Fauci said US health officials should know the severity of Covid-19 cases caused by the Omicron variant in about a week or two and that they are getting their information from counterparts in South Africa, whom the officials have been in near constant contact with.

"They have a number of patients that they're following in the medical facilities, and they assured us that they would know probably in a matter of a week, a week and a half, as to whether or not we're dealing with something that, for the most part is more severe, equally as severe or less severe. It could be either of them," Fauci said. "Right now, it does not look like there's a big signal of a high degree of severity, but it's too early to tell."

It's unclear if Omicron will become the dominant strain in the US, but that's another reason officials are watching cases in South Africa closely.

"You know, it's unfortunate that South Africa has been sort of the epicenter, or at least a recognition of it, but the good news is they are as good as it gets when it comes to scientists and public health people, so they'll be able to give us some very important information, hopefully within the next week or two," Fauci said.

In the meantime, he told Tapper, "the unvaccinated need to get vaccinated and those who are eligible to get boosted should get boosted because we know from experience ... that even with variants that are not specifically directed at by the vaccine, such as the Delta variant, if you get the level of antibody high enough, the protection spills over to those other variants."

Earlier Monday, Biden urged American not to panic over the new variant and encouraged those who have not yet gotten a booster but are eligible to do so.

"We have the best vaccine in the world, the best medicines, the best scientists, and we're learning more every single day. And we'll fight this variant with scientific and knowledgeable actions and speed -- not chaos and confusion," the President said.