MOON TOWNSHIP, Pa. (Reuters) - U.S. President Donald Trump said on Saturday he rejected a demand from Mexican President Enrique Pena Nieto that Trump should say that Mexico would not have to pay for a proposed U.S. border wall.

At a campaign rally in western Pennsylvania for a Republican congressional candidate, Trump gave some details of a testy phone call he had last month with Pena Nieto that led to the postponement of plans for the Mexican leader's first visit to the White House.

Trump brought up the issue when the crowd started chanting, "build that wall."

Trump called Pena Nieto a "really nice guy" who made his request respectfully.

"He said, 'Mr President, I would like you to make a statement that Mexico will not pay for the wall,'" Trump said.

"I said, 'Are you crazy? I am not making that statement,'" Trump said he replied.

When Pena Nieto said yes, Trump said he told him, "Bye, bye. There is no way I'm making that deal."

Mexican Foreign Minister Luis Videgaray repeated Mexico's pledge not to pay for the wall in a post on Twitter late on Saturday night.

"In the call on Feb. 20, President EPN (Enrique Pena Nieto) strongly reiterated what all Mexicans have always said: We will never pay, in any form, for a wall on the border," he wrote. "Under this premise we will continue working constructively on the bilateral relationship with the United States."

The Mexican leader's visit to Washington has yet to be rescheduled. Trump's son-in-law and senior adviser, Jared Kushner, traveled to Mexico City last week to try to smooth over the tensions.

Trump is set to visit a prototype of his long-sought wall in the San Diego area on Tuesday.

(Reporting By Steve Holland; additional reporting by Julia Love; Editing by Daniel Wallis and Rosalba O'Brien)