Donald Trump has signed a revised executive order which will temporarily ban nationals of six Muslim-majority countries from entering the United States.

A new executive order, signed on Monday and set to take effect from March 16, will prevent citizens from Sudan, Syria, Iran, Libya, Somalia, and Yemen entering the US for 90 days.

The US will also halt its refugee admissions programme for the next four months as the government reviews security procedures.

Mr Trump, whose original travel ban was suspended by the Supreme Court, has decided to drop Iraq from the list of affected countries.

According to the Department of Homeland Security (DHS), the concession was made after Iraq agreed to intensified vetting of its citizens.

The new travel ban means that people from the affected countries who are outside the US and without a valid visa from March 16 onwards will not be permitted to enter the country.

Mr Trump's original travel ban proposal, issued by executive order in January, was met with widespread criticism - with many claiming it targeted Muslims.

A temporary suspension of the order was upheld by the US federal appeals court unanimously, and again later by the Supreme Court.

The President warned he would look to issue a new travel ban, and even threatened to take the matter to court.

Mr Trump's new order appears to have made some concessions, including dropping Iraq from the list of banned countries.

A DHS statement revealed that the Middle-Eastern country had, in turn, agreed to allow increased US vetting of its citizens applying for a visa.

The Iraqi government welcomed the move, saying it represented a "positive message" about future relations between the two countries.

The DHS said that the US had "the world's most generous immigration system" which had been "repeatedly exploited by terrorists and other malicious actors who seek to do us harm".

Revealing the details of the new ban, the DHS said: "In order to ensure that the US Government can conduct a thorough and comprehensive analysis of the national security risks posed from our immigration system, the Executive Order imposes a 90-day suspension of entry to the United States of nationals of certain designated countries-countries that were designated by Congress and the Obama Administration as posing national security risks with respect to visa-free travel to the United States under the Visa Waiver Program."

The statement said that the order had been sought to ensure those entering the country "do not bear malicious intent" towards the US.

"This Executive Order ensures that we have a functional immigration system that safeguards our national security," the statement read.

During the 90-day suspension period, the DHS will review how it can in future prevent "terrorist or criminal infiltration" by foreign nationals.

Additionally, a "country-by-country" review of identity and security information will be carried out by DHS.

The statement conceded that those from the banned countries applying for a US visa would be considered on a "case-by-case basis" in exceptional circumstances.

This would include a ban that caused "undue hardship" to an individual applicant, or if it was proved that their entry would not pose a security threat.

Mr Trump's new ban also means that the US's refugee admissions programme will be halted for the next 120 days.

During that time the DHS will review screening procedures "to ensure refugees admitted in the future do not pose a security risk to the United States".