President Donald Trump is leaving the World Economic Forum in Switzerland with bullish talk on the US economy and lashing out at his Senate impeachment trial back in Washington.

Mr Trump called a surprise news conference Wednesday to mark a “tremendous two days” at the glitzy summit of world leaders and financiers in Davos, which has served as a respite from the trial underway in Washington.

“It’s such a hoax,” Mr Trump said of the impeachment case against him.

“I think it’s so bad for our country.”

Mr Trump gave his legal team high marks after more than 12 hours of arguments on procedural motions in which Republicans blocked Democratic efforts to immediately call witnesses and subpoena documents.

But Mr Trump said he wanted to see his aides, including former national security adviser John Bolton and acting chief of staff Mick Mulvaney, give evidence in the Senate.

“Personally, I’d rather go the long route,” he said, referring to calling witnesses in the Senate trial, before suggesting that there were “national security” concerns to allowing their evidence.

A resolution passed early Wednesday by a party line vote allows the Senate to consider calling witnesses only after both sides in the impeachment trial present their cases.

“I thought our team did a very good job,” Mr Trump said, saying he watched some of the proceedings.

Switzerland Davos Forum Trump
US President Donald Trump makes statements to the media (Evan Vucci/AP)

He praised White House Counsel Pat Cipollone’s ”emotion” on the Senate floor, adding: “I was very proud of the job he did.”

Mr Trump repeated his attacks on Democratic House managers serving as prosecutors in the trial, saying that he’d like to “sit right in the front row and stare at their corrupt faces” on the Senate floor during the trial but that his lawyers might have a problem with it.

Democrats say Mr Trump abused his power in his dealings with Ukraine and obstructed Congress in its investigation.

Mr Trump denies doing anything wrong.

Mr Trump opened his news conference with triumphant talk on the American economy and said he is pushing for “very dramatic” changes to the World Trade Organisation.

Mr Trump had announced the unexpected availability during a meeting with Iraqi President Barham Salih.

Mr Trump arrived in Davos on Tuesday.

He addressed the forum and over two days has held meetings with leaders from the European Union, Iraq and Pakistan, among others.

The Republican president said in most of his meetings that trade was on the agenda.