US President Donald Trump's order to restrict people from seven Muslim-majority countries from entering the United States hit a roadblock late yesterday when a federal judge said stranded travellers could stay in the country.

The emergency court ruling was cheered at Boston's Logan International Airport, one of several major US airports where protesters angry with Trump's order gathered.

The American Civil Liberties Union, which sought the temporary stay, said it would help 100 to 200 people with valid visas or refugee status who found themselves detained in transit or at US airports after Trump signed the order late on Friday.

Photo: Reuters

It was a dramatic end to Trump's first week in office, capped by the Republican president's four-month ban on refugees entering the United States and a 90-day hold on travellers from Syria and six other countries.

Trump had promised during his campaign what he called "extreme vetting" of immigrants and refugees to try to prevent terror attacks.

He told reporters in the White House's Oval Office earlier on Saturday that his order was "not a Muslim ban" and said the measures were long overdue.

READ: Fallout from Trump's immigration ban widens

"It's working out very nicely. You see it at the airports, you see it all over," Trump said. The White House could not be immediately reached for comment on the emergency court ruling.

Senior officials at the US Department of Homeland Security told reporters they had not seen the ruling, but said the government would implement any appropriate orders.

Canada takes a different approach

Canadian Prime Minister Justin Trudeau welcomed those fleeing war and persecution even as Canadian airlines said they would turn back US-bound passengers to comply with the immigration ban.

In pointed tweets, Trudeau said refugees were welcome in Canada.

"To those fleeing persecution, terror & war, Canadians will welcome you, regardless of your faith. Diversity is our strength #WelcomeToCanada," Trudeau said on Twitter.

A second tweet, also timed to coincide with outrage over Trump's immigration policy, included a 2015 photo of Trudeau welcoming a Syrian refugee at a Canadian airport.

Confusion abounded at airports around the world on Saturday as officials tried to interpret the new US rules.

Trudeau's office said US authorities had confirmed Canadian passport holders, including dual citizens from the seven countries, would not be affected.

Trudeau has walked a fine line with the Trump administration, avoiding direct criticism while promoting the progressive policies of his one-year-old Liberal government.

The prime minister would discuss Canada's immigration and refugee policies with Trump, Trudeau's press secretary, Cameron Ahmad, said. He did not say when that would be.

Tech companies sound alarm

The ban caught many companies off-guard. 

Netflix Inc Chief Executive Reed Hastings called it "a sad week" and added: "It is time to link arms together to protect American values of freedom and opportunity."

Apple Inc CEO Tim Cook sent a letter to employees saying Trump's order was "not a policy we support" and promised to help affected employees.

"We have reached out to the White House to explain the negative effect on our coworkers and our company," Cook added.

Alphabet Inc's Google urgently called back employees from overseas and told ones who might be affected by the ban not to leave the United States.

CEO Sundar Pichai said in an email to staff that more than 100 Google employees were affected by the order, according to a Google executive.

"We're concerned about the impact of this order and any proposals that could impose restrictions on Googlers and their families, or that could create barriers to bringing great talent to the U.S.," Google said in a statement.

Microsoft Corp President and Chief Legal Officer Brad Smith said in a company-wide email posted on LinkedIn that 76 company employees were citizens of the seven countries in question and held US work visas, and thus were directly affected by the order.

Elon Musk, the South African-born founder of Tesla and SpaceX who met recently with Trump, said on Twitter: "The blanket entry ban on citizens from certain primarily Muslim countries is not the best way to address the country’s challenges."

Airbnb co-founder and CEO Brian Chesky said: "Not allowing countries or refugees into America is not right and we must stand with those who are affected."

Airbnb will provide free housing to anyone not allowed into the United States, Chesky said.

Aaron Levie, the outspoken founder and CEO of online storage company Box Inc, said: "The executive order on immigration is immoral and antithetical to our values."