US President Donald Trump has threatened to withdraw from the World Trade Organisation if "they don't shape up", in his latest criticism of the institution.

Such a move could undermine one of the foundations of the modern global trading system, which the United States was instrumental in creating.

Trump has complained the United States is treated unfairly in global trade and has blamed the World Trade Organisation for allowing that to happen.

He has also warned he could take action against the global body, although he has not specified what form that could take.

Trump has opened up a number of conflicts with trading partners, including Canada, Mexico, China and the European Union, hiking tariffs and threatening more.

[Source:Stuff.co.nz]