The other three nations that have been placed under Level 4 category are  Bhutan, Brunei and Iran.

The CDC places a destination at "Level 4: Covid-19 Very High" risk when more than 500 cases per 100,000 residents are registered in the past 28 days, reports CNN.

Level 4, the CDC's highest, has now swelled to more than 140 places, illustrating the vast range and rapid spread of the Omicron variant around the world this year. In early January, there were around 80 destinations listed there, the American news channel reported.

Malaysia was one of the top travel destinations in Asia before the pandemic started.