Donald Trump used his first Presidents' Day in office to continue trying to talk his way out of comments in which he wrongly implied a terrorist attack had taken place in Sweden.

Meanwhile, people opposed to his populist policies used the US holiday to organise small protests in major cities nationwide.

Trump, who has sought to block travel and immigration from some majority-Muslim countries, set off a storm of ridicule after a rally on the weekend with supporters in Florida, at which he seemed to suggest Sweden's open-door policy on refugees had led to an incident on Friday.

But there was no terrorist attack in Sweden on that day.

After tweeting Sunday that he was in fact referring to a cable news report "concerning immigrants & Sweden," the US president switched yesterday from being defensive to again going on the attack against journalists.

"Give the public a break - The FAKE NEWS media is trying to say that large scale immigration in Sweden is working out just beautifully. NOT!" Trump tweeted from his private resort in Palm Beach, Florida.

Prime Minister Stefan Lofven said yesterday he was "surprised" by Trump's comments.

"We (in Sweden) face huge opportunities as well as challenges," Lofven said at a news conference with Canada's visiting Governor-General David Johnston. The premier added that Sweden ranked high in terms of equality, human development and competitiveness.

"We must all take responsibility for using facts correctly and for verifying any information we spread," Lofven said.

Trump was still at his Mar-a-Lago estate, which he calls the Southern White House and where he spent the weekend ahead of yesterday's federal holiday, an annual observance of the birthday of George Washington (1789-97), the first US president.

"HAPPY PRESIDENTS DAY - MAKE AMERICA GREAT AGAIN!" Trump wrote on Twitter.

He flew back later yesterday to Washington, where the Swedish embassy has sought clarification from the US government about Trump's comments.

Not My Presidents’ Day

A rally organised under the Twitter hashtag #NotMyPresidentsDay yesterday drew hundreds of Trump opponents outside the downtown Los Angeles City Hall.

Demonstrators particularly criticised the new administration's plans for a wall along the entire Mexico border, which includes California.

"Against the wall, sanctuary for all," participants chanted, according to Los Angeles Times coverage.

In Chicago, diverse religious leaders gathered at an inner-city mosque to condemn Trump's immigration policies, the Chicago Tribune reported.

The Reverend Chuck Dahm, a parish priest in a heavily Mexican-American neighbourhood on Chicago's South Side, described a woman with four children who sought his help last week to escape an abusive spouse: "She was afraid to go to court and seek an order of protection because of all the threats coming from the Trump administration."

Thousands of protesters in New York City marched from Central Park to Trump Tower, the president's Manhattan home, holding signs with messages, including "Refugees welcome" and "Build bridges, not walls," the New York Daily News reported.

- dpa