A senior U.S. official has cast doubt over whether U.S. athletes will able to compete at the 2018 Winter Olympics in South Korea amid heightened tensions with the North.

U.S. Ambassador to the United Nations, , said the prospect of U.S. athletes participating in February was an "open question."

When asked by Fox News Wednesday night if it was a "done deal" for American athletes to participate in South Korea, Haley replied: "I have not heard anything about that … But I do know in the talks that we have, whether its Jerusalem or its North Korea, it's always about how we protect U.S. citizens in the area."

In a tweet Thursday, White House press secretary Sarah Huckabee Sanders said American athletes do plan to participate.

UPDATE: The U.S. looks forward to participating in the Winter Olympics in South Korea. The protection of Americans is our top priority and we are engaged with the South Koreans and other partner nations to secure the venues.

The Winter Olympics are due to be held from February 9-25 in Pyeongchang. The South Korean town is approximately 50 miles from the heavily fortified demilitarized zone (DMZ) on the border between the two Koreas.