Citizens of seven mainly Muslim countries banned from the United States by President Donald Trump can resume boarding U.S.-bound flights, major airlines said on Saturday, after a Seattle judge blocked the executive order.

The ruling gave hope to some Middle East travellers but left them unclear how long the new travel window might last. Trump denounced the judge on Twitter and said the decision would be quashed.

"The opinion of this so-called judge, which essentially takes law-enforcement away from our country, is ridiculous and will be overturned!" the president said.

The travel ban, which Trump says is needed to protect the United States against Islamist militants, has sparked travel chaos around the world and condemnation by rights groups who have called it racist and discriminatory.

"Interesting that certain Middle-Eastern countries agree with the ban. They know if certain people are allowed in it's death & destruction!" Trump tweeted. "When a country is no longer able to say who can, and who cannot, come in & out, especially for reasons of safety & security - big trouble!"

In the wake of Friday's ruling, Qatar Airways was the first to say it would allow passengers from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen to resume flying to U.S. cities if they had valid documents.

Fellow Gulf carriers Etihad and Emirates said they would do the same, as did Air France, Spain's Iberia and Germany's Lufthansa. Officials in Lebanon and Jordan said they had received no new instructions on the issue.

The White House said it planned to appeal as soon as possible.

Ibrahim Ghaith, a Syrian barber who fled Damascus in 2013, told Reuters in Jordan: “Today we heard that the measures may have been abolished but we are not sure if this is just talk. If they go back on the decision, people will be overjoyed."

Iraqi refugee Nizar al-Qassab told Reuters in Lebanon: "If it really has been frozen, I thank God, because my wife and children should have been in America by now."

The 52-year-old said his family had been due to travel to the United States for resettlement on Jan. 31. The trip was cancelled two days before that, and he was now waiting for a phone call from U.N. officials overseeing their case. "It's in God's hands," he said.

"RACE AGAINST TIME"

Two Sudanese travellers told Reuters they were trying to travel as soon as possible, fearing the ban might be reinstated.

“I’m in a race against time," said a 31-year-old female academic who declined to be named for fear of any consequences.

"Today I face a real problem in Khartoum because the international airlines are refusing to sell me a ticket to travel for fear of contradicting the President’s decision. Now I am going from one airline company to another to convince them about the court’s decision,” she said.

A 34-year-old Sudanese engineer, who also did not want to be named, said: "After the court’s decision I am now trying to leave as fast as possible before the situation changes once more."

U.S. Customs and Border Protection told airlines they could board travelers affected within hours of Friday's ruling, but budget airline Norwegian, which operates transatlantic flights including from London and Oslo, said many uncertainties remained about the legal position.

"It's still very unclear," spokeswoman Charlotte Holmbergh Jacobsson said. "We advise passengers to contact the U.S. embassy ... We have to follow the U.S. rules."

In Cairo, aviation sources said Egypt Air and other airlines had told their sales offices of Friday's ruling and would allow people previously affected by the ban to book flights.

But for some who had changed their travel plans following the ban, the order was not enough reassurance.

Josephine Abu Assaleh, who was stopped from entering the United States last week with five members of her family, was hesitant to express any hope in the court ruling as she awaited word from her lawyers.

"I will not say if I have hope or not. I wait, watch, and then I build my hopes. We left the matter with the lawyers. When they tell us the decision has been cancelled, we will decide whether to go back or not,” she told Reuters in Damascus, speaking by telephone.

Abu Assaleh, 60, and her family only learnt of Trump’s order after landing at Philadelphia International Airport with U.S. visas that were granted in 2016, some 13 years after they initially made their applications.

VISA SUSPENSIONS

Trump's order caused chaos at airports across the United States last week. Virtually all refugees were also barred, upending the lives of thousands of people who had spent years seeking asylum in the U.S.

The State Department said on Friday that almost 60,000 visas were suspended following Trump's order. It was not clear whether that suspension was automatically revoked or what reception travelers with such visas might get at U.S. airports.

The Washington state lawsuit was the first to test the broad constitutionality of Trump's executive order. Judge James Robart, a George W. Bush appointee, explicitly made his ruling apply across the country, while other judges in similar cases have so far issued orders concerning only specific individuals.

The challenge in Seattle was brought by the state of Washington and later joined by the state of Minnesota. The judge ruled that the states have legal standing to sue, which could help Democratic attorneys general take on Trump in court on issues beyond immigration.

Washington's case was based on claims that the state had suffered harm from the travel ban, for example students and faculty at state-funded universities being stranded overseas. Amazon.com and Expedia, both based in Washington state, had supported the lawsuit, asserting that the travel restrictions harmed their businesses.

Tech companies, which rely on talent from around the world, have been increasingly outspoken in their opposition to the Trump administration's anti-immigrant policies.

Judge Robart probed a Justice Department lawyer on what he called the "litany of harms” suffered by Washington state’s universities, and also questioned the use of the Sept. 11, 2001, attacks on the United States as a justification for the ban.

Robart said no attacks had been carried out on U.S. soil by individuals from the seven countries affected by the travel ban since that assault. For Trump’s order to be constitutional, Robart said, it had to be “based in fact, as opposed to fiction.”

The White House said in a statement: “At the earliest possible time, the Department of Justice intends to file an emergency stay of this outrageous order and defend the executive order of the president, which we believe is lawful and appropriate."

It added: "The president’s order is intended to protect the homeland and he has the constitutional authority and responsibility to protect the American people."

Washington Governor Jay Inslee celebrated the decision as a victory for the state, adding: "No person - not even the president - is above the law." —Reuters