US President Trump ' title='Donald Trump '>Donald Trump marked his 100th day in office in a rally in Pennsylvania, where he focused on his long-running antagonism with the news media and also touted his administration's "historic progress", a report said.

In his opening remarks at the rally in Harrisburg on Saturday evening, he mentioned the "big gathering" in Washington - the White House Correspondents' Association (WHCA) dinner, which he declined to attend and dismissed the event as "a large group of Hollywood actors and Washington media" who he said were "consoling each other in a hotel ballroom", The Washington Post reported.

"I could not possibly be more thrilled than to be more than 100 miles away from Washington's swamp, spending my evening with all of you, and with a much, much larger crowd and much better people, right?" Trump said at his event, not mentioning that he attended the dinner in 2011 while a reality television star and was repeatedly roasted by then-President Barack Obama.

In February, Trump had announced that he will not appear at the WHCA dinner this year, a break with past presidents, adding his absence from the event is for the best.

Trump then went on to needle the media, touching on familiar themes and picking on his standard targets.

He dismissed news channels CNN and MSNBC as "fake news".

Trump decried what he again called "the totally failing New York Times", falsely claiming that the organisation was "forced to apologise" for its coverage of the 2016 election, a claim he has made before.

He also took a shot at the daily's headquarters, which he called an "ugly office building in a crummy location".

Trump made clear that he was trying to draw a direct contrast with the news media, saying that they deserved "a very, very big fat failing grade" for their coverage, before shifting to a discussion of his administration's actions, reports The Washington Post.

Trump also vowed that he would make "a big decision" on the historic Paris climate agreement in the next two weeks.

"I will be making a big decision on the Paris Agreement in the next two weeks. We will see what happens," Efe news quoted Trump as saying in the rally.

Meanwhile, Pennsylvania Democratic and liberal protest groups turned out for an opposition rally and march in Harrisburg on Saturday to protest Trump, who chose to host his event in the same city he referred to as "a war zone" during the campaign.

Chants included cries of "Hey hey, ho ho! Trump ' title='Donald Trump '>Donald Trump has got to go!" and "No Trump! No KKK (Ku Klux Klan)! No fascist USA!", The Washington Post reported.

Anti- Trump protests and events were planned in other cities across the country as well, including Utica and Syracuse, New York, Boston, San Francisco and Chicago.

In Washington, crowds gathered for the Peoples Climate March in support of environmental protection efforts, some of which have been rolled back during Trump's first 100 days.