Lower courts had deemed the ban unconstitutional, but the US top court reversed the decision in a 5-4 ruling, CNN reported.

"The Proclamation is squarely within the scope of Presidential authority," Chief Justice John Roberts wrote.

This is the third version of the travel ban. It was issued in September -- after previous bans had ricocheted through the courts -- and restricts entry from seven countries to varying degrees: Iran, North Korea, Syria, Libya, Yemen, Somalia and Venezuela.

Chad was originally on the list but it was recently removed after having met baseline security requirements.

Challengers, including the state of Hawaii, had argued that the proclamation exceeded the President's authority under immigration law as well as the Constitution.

They also used President Donald Trump's statements during the campaign, when he called for a ban on travel from all Muslim-majority countries, but Roberts dismissed those concerns.