WASHINGTON - Donald Trump is set to meet his first world leader, Britain's Theresa May, since taking office.

The prime minister is a friendly ally who hopes to nudge the populist president toward the political mainstream.

The visit Friday comes a day after Mexican President Enrique Pena Nieto called off his own trip to Washington, planned for next week, amid wrangling over who will pay for Trump's planned wall along the U.S.-Mexico border.

May's meeting with the president in the Oval Office is being hailed by the British government as a sign that the trans-Atlantic "special relationship" is valued by the new administration.

The White House says May and Trump will hold talks, followed by a press conference and a working lunch.