The US has said it intends to negotiate three new trade agreements with Japan, the European Union and the UK in a bid to reshape trade policies under the Trump administration.

A statement from US trade representative Robert Lighthizer said negotiations with Japan should start within three months, but talks with Britain will have to wait until Brexit is official in March 2019.

"We are committed to concluding these negotiations with timely and substantive results for American workers, farmers, ranchers, and businesses," said Mr Lighthizer.

The US said it wants to "address both tariff and non-tariff barriers" and achieve "free, fair and reciprocal trade", the statement to Congress said.

Responding to the news, a UK government spokesperson said: "The UK welcomes the US administration's confirmation that it intends to begin negotiations for a Free Trade Agreement with the UK once we have left the EU."

Analysts believe US president Donald Trump has been emboldened to continue negotiating fresh trade agreements to support his 'America First' policies after successfully finalizing a new deal between the US, Canada and Mexico that will replace the North American Free Trade Agreement (NAFTA).

However, tensions with China are ongoing after both countries imposed tariffs on each other's products, something experts have said could threaten the stability of the world economy.

If Mr Trump could reach a deal with Japan, it would be the first time the world's first and third largest economies have come to a trade agreement.

Former president Barack Obama had tried to create a Trans-Pacific Partnership with multiple countries including Japan and the US, but Mr Trump pulled America out of negotiations as soon as he reached office.