Mexican President Enrique Peña Nieto on Thursday canceled his meeting next week with President Donald Trump after Trump warned he should not visit Washington, DC, if Mexico was “unwilling to pay” for a wall on its shared border with the US.

“This morning we have informed the White House that I will not attend the meeting scheduled for next Tuesday with the @POTUS,” Peña Nieto tweeted, according to an online translation.

Trump, at a Republican retreat in Philadelphia, said later Thursday that both leaders had “agreed” to cancel the meeting, saying it would be “fruitless.”

The cancellation came after Trump tweeted that Peña Nieto should not meet with him unless Mexico was willing to finance the massive construction project.

“The U.S. has a 60 billion dollar trade deficit with Mexico,” Trump wrote on Twitter. “It has been a one-sided deal from the beginning of NAFTA with massive numbers of jobs and companies lost.”

Trump continued: “If Mexico is unwilling to pay for the badly needed wall, then it would be better to cancel the upcoming meeting.”

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Peña Nieto was initially scheduled to meet with Trump on Tuesday in what would be the duo’s first bilateral meeting since the new US administration took office.

Building a wall on the US-Mexico border was one of the chief promises Trump made to the American people during the 2016 campaign. He repeatedly promised that he would use trade advantages held by the US to force Mexico to finance it.

Trump said in an interview with ABC News broadcast on Wednesday that he would like construction of the barrier to begin within “months.”

At the Department of Homeland Security on Wednesday, Trump signed two executive orders related to immigration and the construction of the wall. He told department employees that the moves would help “restore the rule of law.”

“A nation without borders is not a nation,” Trump said. “Beginning today, the United States of America gets back control as it gets back its borders.”

During his interview with ABC News, Trump dodged the question when anchor David Muir pressed him on whether American taxpayers would initially foot the bill for construction of the wall.

“All it is is we’ll be reimbursed at a later date from whatever transaction we make from Mexico,” Trump said.

Muir mentioned that Peña Nieto had said he would refuse to pay for the wall, but Trump stood firm.

“I think he has to say that. He has to say that,” Trump said. “But I’m just telling you there will be a payment. It will be in a form, perhaps a complicated form, and you have to understand what I’m doing is good for the United States. It’s also going to be good for Mexico. We want to have a very stable, very solid Mexico.”

Speaker Paul Ryan told MSNBC on Wednesday that there were “a lot of different ways” the US could compel Mexico to “contribute” to the costs associated with building the wall.

Pamela Engel contributed to this story.