A federal judge in Washington state on Friday temporarily blocked President Donald Trump's executive order that put a hold on entry to the U.S. of people from seven predominantly Muslim nations.
The temporary restraining order applies nationwide, state Attorney General Bob Ferguson's office said.
"The Constitution prevailed today," Ferguson said in a statement. "No one is above the law — not even the President."
The restraining order will be in effect until U.S. District Court Senior Judge James L. Robart considers a legal challenge filed by the attorney general, Ferguson's office said.
But the White House press secretary said the administration would seek an emergency stay at the earliest possible time, and initially called the judge's action an "outrageous order." An updated statement issued a short time later dropped the term "outrageous."
"The president's order is intended to protect the homeland and he has the constitutional authority and responsibility to protect the American people," both statements said.
A Department of Homeland Security official had originally told NBC News that the judge's order would have no immediate practical effect. All previously issued visas from the seven affected countries were canceled by last week's executive order, the official said, meaning people would have to reapply.
Trump said the order, which he signed Jan. 27, would suspend entry for 90 days of nationals of Iraq, Syria, Sudan, Iran, Somalia, Libya, and Yemen. He said the order was necessary to keep Americans safe from terrorism. Critics have called it a "Muslim ban," which the president has denied.
The Department of Homeland Security said in a statement Friday that the "pause" would not apply to lawful permanent residents or dual citizens.
Washington state announced on Monday that it was filing a federal lawsuit challenging the executive order.
"The states have met their burden of demonstrating that they face immediate and irreparable injury as a result of the signing and implementation of the executive order," Robart wrote in the restraining order.
The president's executive order also temporarily halted the U.S. refugee program, and indefinitely suspended the admission of Syrian refugees.
"Judge Robart's decision, effective immediately, effective now, puts a halt to President Trump's unconstitutional and unlawful executive order," Ferguson said. "It puts a stop to it immediately, nationwide."
Robart was nominated by President George W. Bush in 2003 and was confirmed by the Senate in 2004.
Implementation of Trump's order caused chaos at airports over the weekend. Among those reported temporarily detained were an Iraqi refugee who worked with the U.S. government, green card holders, students and professors. Protests erupted at several large airports across the country after Trump signed the order.
The ruling in Washington state came after a federal judge in Boston refused to extend a temporary injunction against the immigration order. The judge in that case called arguments about the nation's history of immigration as well as security concerns strong, but said the plaintiffs didn't show they were likely to succeed on the merits.
Amnesty International, one of several groups who opposed the executive order, said of the Washington case: "This decision is a short-term relief for thousands of people whose lives have been upended, but Congress must step in and block this unlawful ban for good."
Sen. Chuck Schumer, a Democrat and Senate Minority Leader, called the judge's restraining order "a victory for the Constitution and for all of us who believe this un-American executive order will not make us safer," and said Trump should rescind it.
Trump earlier Friday appeared to reference his controversial order in a Tweet that read: "We must keep "evil" out of our country!"
Ferguson, the Washington attorney general, blasted Trump's order when asked whether there could be any confusion as to the Seattle judge's late afternoon order.
"I'll tell you where there's been confusion — the president's executive order. That's what caused confusion," he said. "I'm sorry, there's no other way to put it: It's Keystone Cops. It really is. And that's not just me speaking, that's Republican members of Congress."