The political standoff between North and South Korea is also causing tension within the Olympic movement, with several countries expressing concern over next year's Winter Games in Pyeongchang, South Korea.
The US Olympic Committee has sent a letter to its athletes telling them there is no reason at this stage to suggest the country won't participate in the Games.
But USOC chief security officer Nicole Deal does write that provocations that have existed between the United States and North Korea are likely to persist for the foreseeable future.
"(They) should not be dismissed as insignificant nor feared as precursors of an inevitable conflict," she wrote.
Deal also writes that the USOC is reviewing crisis management plans that address a range of potential scenarios "to ensure our athletes, and our entire delegation, are safe."
Meanwhile, France's Olympic Committee on Friday played down security concerns, after the French government on Thursday became the first to publicly raise the possibility of skipping the Olympics on safety grounds.
"With the safety and the security of the athletes at the top of its priorities, the IOC indicates that nothing at this time leads to believe that the organising conditions of the winter Olympic Games do not comply with these imperatives," the FOC said.
The Pyeongchang Olympics will be held just 80 km from the demilitarised zone between North and South Korea, the world's most heavily armed border.
North Korea said on Friday it might test a hydrogen bomb over the Pacific Ocean after US President Donald Trump threatened to destroy the reclusive country.
"We are monitoring the situation on the Korean peninsula and the region very closely." an International Olympic Committee spokesman said.
"Athletes' safety and security are of course a primary concern for the IOC. This is why ...we continue to be in touch with the heads of state concerned."
"In none of the discussions has anybody expressed any doubt about the Olympic Games 2018."
The IOC said it was helping North Korea prepare its athletes for the Games and would cover costs of their equipment if needed.
