President Donald Trump on Monday signed a revised version of his January 27 executive order suspending US entry for all refugees as well as travelers from a group of Muslim-majority countries.

Among the revisions is the removal of Iraq from the list of targeted nations, which now include Iran, Libya, Somalia, Sudan, Syria and Yemen.

The new order will enter into force at 12:01 am Washington time on March 16 and will replace the controversial measure he signed in late January that was subsequently blocked by a court decision.

The president has decided to allow Iraqis to enter this country because the Iraqi government has promised to cooperate in the vetting of its nationals, according to top US government officials who requested anonymity during a conference call with the press.

In a press conference following the signature of the ban, Secretary of State Rex Tillerson said that Iraq was not included in the new order because it "is an important ally in the fight to defeat ISIS," adding that Baghdad "will be implementing (multiple security measures) to achieve our shared objective of preventing those with criminal or terroristic intent from reaching the United States."

Despite the fact that Iraq has been removed from the list, a ban on issuing visas for the other Muslim-majority nations on the list remains in place for 90 days.

In contrast to the earlier order, this one specifies that citizens of those six nations may enter the US if they had a valid visa before 5 pm on Jan. 27.

That matter had not been clarified in the earlier order and chaos resulted at airports around the world when people from those nations holding valid visas were prevented from traveling to the US.

The president also eliminated any reference to Christians in the new executive order, that group being one that he had tried to protect in his first order.

In the earlier executive order, Trump established that Syrian Christians could enter the United States but entry for other refugees from Syria along with the faithful of other religions was indefinitely halted.

The revised ban was announced ti the press by the heads of the agencies that will be tasked with overseeing its implementation.

During the press conference, Secretary of State Rex Tillerson insisted that the new executive order on immigration signed earlier in the day by President Donald Trump is "vital" for the country's security and asked Washington's allies around the world to "understand" that it is a "temporary" effort to strengthen immigration control.

"While no system can be completely infallible, the American people can have high confidence we are investigating ways to improve the vetting process and thus keep terrorists from entering our country," said Tillerson, adding that the order will strengthen security for the US and its allies.

Attorney General Jeff Sessions, upon addressing reporters, emphasized that "(M)ore than 300 people who came here as refugees (since the Sept. 11, 2001, terrorist attacks) are under FBI investigation for potential terrorism-related activities."

He said that three of the nations on the list are state sponsors of terrorism and the other three have provided refuge to terrorists and have governments that have lost control of their territories due to groups like the Islamic State, Al Qaeda and their affiliates.

The first travel ban was temporarily halted by a federal judge just days after it was issued. The ninth circuit federal appeals court upheld the ruling last month, denying the justice department’s request to reinstate it.

On Monday justice department attorneys informed the ninth circuit they believed the new order was unaffected by the court’s previous ruling. Bob Ferguson, the Washington state attorney general who brought the case against the federal government said in a statement he was “carefully reviewing” the new order.