President Donald Trump has threatened to pull the United States out of the World Trade Organisation if it does not “shape up”.

His remarks, made in an interview with Bloomberg News on Thursday, were the latest in a series of attacks on institutions of the global order that the US helped to build after World War II.

“If they don't shape up, I would withdraw from the WTO,” Trump told the news agency, describing the agreement to set the organisation up as “the single worst trade deal ever made”.

Trump, who has previously criticized the WTO's dispute settlement system as being unfavorable to the US, said Washington had “rarely won a lawsuit” there although things began changing last year.

“In the last year, we're starting to win a lot,” he said. “You know why? Because they know if we don't, I'm out of there.”

China, which is currently embroiled in a trade war with the US, joined the WTO in 2001 — a move which US Trade Representative Robert Lighthizer has described as a mistake.

Trump made the threat as Washington presses challenges at the WTO against trading partners that have fought back against tariffs on importers that were imposed by the Trump administration.