President Donald Trump is replacing his ban on travellers from six majority-Muslim countries with more tailored restrictions on travellers from additional countries.

The Department of Homeland Security has recommended the president impose the new, targeted restrictions on foreign nationals from countries it says refuse to share sufficient information with the US or haven't taken necessary security precautions.

The new travel restrictions could include indefinite bans on entry until vetting procedures and security cooperation improves, officials said. They will go into effect as soon as Sunday, after the conclusion of a 90-day policy review undertaken as part of the administration’s original travel ban, reported The New York Times.

The restrictions could vary by country to country, stated the report citing officials.

Trump will soon announce the list of countries subject to the travel restrictions, they stated.

However, they declined to say whether the list would include all six countries from which travel was temporarily banned by a revised executive order in March: Iran, Libya, Somalia, Sudan, Syria and Yemen.

The president hinted that the changes were coming in a tweet after a crude bomb exploded on a London Underground train last week: “The travel ban into the US should be far larger, tougher and more specific.”

Officials said Trump was given a “decision brief” on the travel ban by senior officials during a meeting Friday at the president’s Bedminster club, said the NYT report.

The announcement is the culmination of the biggest legal challenge to Trump’s presidential authority since he took office.

It came just over two weeks before the Supreme Court is set to hear arguments in lawsuits that claim Trump exceeded his authority and defied the constitution by banning entry from the six countries, it added.