PRESIDENT Donald Trump marked his 100th day in office by claiming historic action on his agenda, renewing promises on health care and taxes and attacking the news media for misleading Americans.

In his morning radio address, Trump issued an assurance: “My only allegiance is to you, our wonderful citizens.” To supporters at a rally in Pennsylvania, he promoted American power and patriotism while emphasising such priorities as American manufacturing, better trade deals, a border wall with Mexico and a still-to-be defined tax cut plan.

“We are not going to let other countries take advantage of us any more,” he said in Harrisburg at the Pennsylvania Farm Show Complex and Expo Centre. “From now on it’s going to be America first.”

Trump’s 100th day events were set in a politically important state that he won with 48 per cent of the vote. It was the first time Pennsylvania had voted for a Republican presidential candidate since George HW Bush in 1988.

Trump visited the AMES Companies in Pennsylvania’s Cumberland County, a shovel manufacturer since 1774. With that backdrop he signed an executive order directing the Commerce Department and the US trade representative to conduct a study of US trade agreements. The goal is to determine whether America is being treated fairly by its trading partners and the 164-nation World Trade Organisation.

Trump’s rally on Saturday night in Harrisburg offered a familiar recapitulation of what he and aides have argued for days are administration successes, including the successful nomination of Neil Gorsuch to the Supreme Court, his Cabinet choices and the approval of construction of the Keystone XL pipeline.

Meanwhile, North Korea’s missile launch on Saturday signalled its continued defiance against the US, China and other nations, on which Mr Trump tweeted: “Bad!” At the 100-day mark, polls show that Trump’s supporters during the campaign remain largely in his corner.

Trump said: “It’s a false standard, 100 days, but I have to tell you, I don’t think anybody has done what we’ve been able to do in 100 days, so we’re very happy.”