The administration of President Donald Trump loosened a restriction on legal residents holding green cards returning to the United States from overseas travel after a weekend of confusion, protests and worldwide outcry over a sweeping immigration order.

The executive order signed by Trump on Friday afternoon curtailing travel by citizens of seven predominantly Muslim countries was met with befuddlement at airports as customs and immigration agents grappled with the new rules.

Protests erupted around the country, lawsuits were filed and a federal judge blocked deportation of those detained under the order, which drew criticism from immigration and human rights activists, Democratic lawmakers and leading Republicans.

Senator Bob Corker, the Republican chairman of the U.S. Senate Foreign Relations Committee and a Trump supporter, said the president's order had been poorly implemented, particularly for green card holders.

"The administration should immediately make appropriate revisions, and it is my hope that following a thorough review and implementation of security enhancements that many of these programs will be improved and reinstated," Corker said.

The Department of Homeland Security, which oversees customs, border and immigration agencies, struggled to interpret and implement the order over the weekend.

The fate of green card holders was a particular point of confusion, with both DHS and administration officials saying citizens of the seven affected countries holding U.S. green cards would be denied re-entry without a rescreening process.

All U.S. green card holders, who are legal permanent U.S. residents, were included in Trump's executive action and were required to undergo additional screening before re-entering the country, administration officials said on Saturday.

Late on Sunday, Homeland Security said those legal permanent residents would be admitted, subject to security checks.

"Importantly, however, lawful permanent residents of the United States traveling on a valid I-551 will be allowed to board U.S. bound aircraft and will be assessed for exceptions at arrival ports of entry, as appropriate," it said in a statement.

Senior Trump adviser Kellyanne Conway on Monday said the green card guidelines were not altered but needed clarification. "It wasn't a rollback," she said on CNBC.

Trump defended the executive order as in the interests of national security and said the seven countries targeted had been identified as "sources of terror" by the Obama administration.

In a statement released after a chaotic weekend, the new Republican president expressed compassion for Syrians affected by civil war and others fleeing oppression and stressed that the United States will begin issuing visas to all countries once security measures were reviewed.

Trump rejected criticism that the order amounted to a Muslim ban, saying more than 40 majority Muslim countries were not affected.

In a pair of Twitter posts early on Monday, Trump appeared to blame airport confusion on protesters, Democratic Senator Chuck Schumer, who had teared up while talking about the ban, and even a computer system failure at Delta Airlines late Sunday.

"Only 109 people out of 325,000 were detained and held for questioning. Big problems at airports were caused by Delta computer outage ... protesters and the tears of Senator (Chuck) Schumer. Secretary Kelly said that all is going well with very few problems. MAKE AMERICA SAFE AGAIN!" he wrote.

The issue hung over the Screen Actors Guild awards in Hollywood, where stars slammed Trump for restricting entry.

"Because I love this country, I am horrified by its blemishes, and this immigrant ban is a blemish," said Julia Louis-Dreyfus, who won best comedy TV actress for her portrayal of U.S. President Selina Meyer on HBO's political satire "Veep."