TAMPA, Fla. (WFLA) — Concerns are rising across the world due to the spread of a new COVID-19 variant first identified in South Africa.

The United States is among several countries and governing bodies that have moved to block flights from several African countries in hopes to stem the spread of Omicron.

“As a precautionary measure until we have more information, I am ordering additional air travel restrictions from South Africa and seven other countries. These new restrictions will take effect on Nov. 29. As we move forward, we will continue to be guided by what the science and my medical team advises,” President Joe Biden said in a statement.

The new travel restrictions don’t apply to returning U.S. citizens or permanent residents. However, they will have to test negative before their travel. The affected countries are South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi.

“When you diminish or stop or block travel from a particular country, there’s a reason for that. It’s to give you time to do things. So don’t let this decision that was made about blocking the travel from certain countries go without a positive effect. And the positive effect is to get us better prepared to rev up on the vaccination, to be really ready for something that may not actually be a big deal, but we want to make sure that we’re prepared for the worst and that’s what we should be doing,” Dr. Anthony Fauci said.

Biden and health officials recommend Americans get vaccinated or get their booster shot to help curb the virus’ spread, and to avoid gatherings or work if you’re sick.

The new variant is said to have over 30 mutations, a significantly higher number than the Delta variant. There are two confirmed cases in Ontario, Canada, which were detected for the first time on Sunday.

The White House’s COVID-19 responsive will hold a briefing to share the latest developments on Monday.