President Donald Trump signed a new executive order Monday that restricts U.S. entry of nationals from six Muslim-majority countries for three months and suspends refugees for four months while the Homeland Security, State and Justice departments tighten vetting procedures. 

The new order will go into effect at midnight on March 16 and will apply to nationals of Iran, Libya, Sudan, Somalia, Syria, and Yemen who don’t already have a valid U.S. visa to enter the country.

A fact sheet on the new order is available here.

Iraq, which was included in a Jan. 27 executive order restricting travel, has been removed from the new order after the Iraqi government agreed to step up cooperation and provide more information on its citizens, a senior Homeland Security official told reporters on a conference call.

Trump decided to issue the new order because of “complications posed by having to comply with so many temporary restraining orders, preliminary injunctions and a quagmire of legal action” that halted implementation of the original order, the Homeland Security official said, speaking on the condition of anonymity while briefing reporters.

The six countries targeted for travel restrictions were chosen because their residents overstay their U.S. visas at rates “significantly higher than the worldwide average,” the DHS official said. In addition, those countries also refuse to cooperate in taking back their residents on a timely basis, “so that we’re stuck with their nationals.”

The new order “is very much prospective in nature and we’re talking about the future entry of individuals into the United States,” the official said. “We’re not talking about lawful permanent residents, and those who have current valid visas, or folks who are already in the United States.”

Unlike the Jan. 27 order, Monday’s action does not permanently ban the entry of Syrian refugees.

Trump promised during the campaign to cease the flow of certain refugees into the United States and force prospective immigrants from countries linked to terrorism to undergo “extreme vetting.” He proposed a “total and complete shutdown” of immigration by Muslims, a move widely condemned by members of both parties.

The rollout of the order sparked protests across the country and left many travelers stranded at airports. The State Department said an estimated 60,000 people from the seven majority-Muslim countries trying to get into the United States had their visas revoked.

Lawsuits were filed in federal courts across the country. The U.S. Court of Appeals for the 9th Circuit upheld a lower court ruling and refused to reinstate the Jan. 27 order nationwide, which prompted the Trump administration to draft the second order.

The visa restrictions imposed by the new order will remain in place for 90 days during which officials from DHS and State will examine gaps in information received from visa applicants not only from the six countries mentioned in today’s order but also from other countries in the world, the Homeland Security official said.

At the end of the 90-day period, State and Homeland “will make recommendations about any countries that could be included on a future suspension of entry,” the official said.

DHS and Justice Department officials said that the FBI, in addition to the 1,000 ongoing investigations of potential terrorist plots, is also examining 300 refugees for terrorism-related activities.

Officials declined to say how many of those 300 refugees were from the six countries targeted by today’s executive order, and also declined to say whether any of the 300 had become legal permanent residents or citizens since being admitted as refugees.

— Dean DeChiaro contributed to this report.