NEW YORK (REUTERS) - British Prime Minister Theresa May and US President Donald Trump discussed their will to strike a "big and ambitious" trade deal after Britain's withdrawal from the European Union, May's office said on Wednesday (Sept 26).

A trade deal with the United States is seen as an important way to help offset the economic impact of leaving the EU next March. May's government has long touted the freedom to strike such deals independently of the EU as the main economic benefit of Brexit.

"The president and the prime minister began by discussing their mutual desire to form a wide-ranging trade deal," the prime minister's office said in a statement after a meeting with Trump in New York on the sidelines of the United Nations General Assembly.

"They agreed that Brexit provides a wonderful opportunity to strike a big and ambitious UK-US Free Trade Agreement."

Evidence that Trump is supportive of such a deal could boost May's struggle to win over critics who say her exit plan is unworkable, and soothe financial markets which expect severe disruption if she is unable to get a Brexit deal.

However, a White House readout of the meeting did not mention the trade deal, saying only that the pair had "discussed a variety of global challenges."

The bilateral meeting came shortly after May had challenged Trump's anti-globalism stance with a defense of multilateralism in her address to the General Assembly.

May's officials said the speech was not aimed at Trump and had been largely written before she had seen his remarks.