Several mutated strains of the virus have emerged around the world in recent months, according to the World Health Organization. Most recently, a new variant that appears to be more infectious was discovered in the United Kingdom and has since been found elsewhere, including in at least four U.S. states. Another separate strain was also discovered in South Africa last month.
On Monday, Gov. Andrew Cuomo announced that the first case of the new variant that was discovered in the U.K. was found in upstate New York.
"It's a very big concern, and it's a strain that is obviously around the world and, you're going to find over the days ahead, it's in many locations in the United States," Osterholm, an epidemiologist and director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said on "Squawk Box."
"And it's the first of what will likely be a number of these strains that are emerging as we're at this point in the pandemic," he added.
The new strain discovered in the U.K. doesn't appear to make people more severely sick, officials from the Centers for Disease Control and Prevention said last week, but officials said they believe it does spread more easily. That means it could further stress hospitals that are "already heavily burdened," Dr. Henry Walke, the CDC's Covid incident manager, said last week on a conference call with reporters.
CDC officials added that the currently authorized Covid vaccines are believed to be effective against the new variant discovered in the U.K., and efforts to confirm that are underway.
The CDC has partnered with academic centers across the country to test samples from across the U.S. for new strain of the virus, Walke said.
U.K. Prime Minister Boris Johnson on Monday announced a new national lockdown order on England until at least mid-February in hopes of slowing the spread of the new variant. He said the nation's top medical officers believe the strain is between 50% and 70% more transmissible compared with previous versions.
"With most of the country already under extreme measures, it's clear that we need to do more together to bring this new variant under control while our vaccines are rolled out," Johnson said during a televised announcement.
It remains unclear whether more restrictions will be implemented on a local or regional level in the U.S. in response to the discovery of the new strain, Osterholm said Tuesday. He added that the U.S. already has "a number of measures put in place to try to limit transmission."
Infectious disease experts have warned that the more widely the virus is spreading, the more opportunities it has to mutate into a more infectious or serious strain.
"This is a challenge and it's one that, as we're watching" in Europe with the new variant, has "been made only more acute by the fact that this virus now, the new strains, are transmitting even more effectively than the ones before," Osterholm said.
— CNBC's Noah Higgins-Dunn contributed to this report.