Trump had flashed a folded copy of the deal to reporters this week, and said it's "the agreement that everybody says I don't have".
However, Mexico has not accepted that the United States send it an unlimited number of asylum seekers, Foreign Minister Marcelo Ebrard said, ahead of meetings with US officials on Friday to determine details of the expansion.
The United States has doubled the number of asylum seekers it sends back each day to Mexico from El Paso, Texas, a Mexican immigration official said on Friday, in the first sign of action following a deal struck to avert US tariffs last week.
The flow of Central American migrants fleeing poverty and crime has increased since the end of 2018, with caravans of thousands crossing Mexico, mainly on foot, to reach the USA border.
Photojournalists managed to capture a few sentences of the document, but the full contents had not previously been revealed.
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Last month, the Duchess of Sussex - who is American - celebrated her first US Mother's Day by sharing a picture of Archie's feet . The baby hadn't yet been born when the United Kingdom had its Mother's Day this year. "Happy Father's Day! " reads the caption.
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ET, Edesur said electricity was being restored to parts of Argentina and that the process would take a couple of hours. In Buenos Aires , the Constitucion railway station was empty, with trains halted, Bloomberg reported.
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While Ames and Harper were not arrested, they were taken to the police station and were detained for quite a while. While the family's claim said the incident happened "on or about May 29", the police statement said it was May 27.
According to a joint declaration issued by the State Department and Mexico last week, Mexico will take "unprecedented steps to increase enforcement to curb irregular migration, to include the deployment of its National Guard throughout Mexico, giving priority to its southern border". Mexico has been doing a terrific job.
Speaking during Ebrard's testimony before Congress, Senator Dulce Maria Sauri of opposition party PRI rejected the foreign minister's claim that Mexico had not signed a binding agreement.
Safe third county mandates that migrants must seek asylum in the country they first enter. But the joint statement sent out by the State Department did not mention trade, and the Mexican ambassador to the USA dodged a question about trade in an interview last Sunday.
They included the speaker of Congress, Porfirio Munoz Ledo, who says the Mexican government and Trump administration "want to turn our country into a cage" for migrants.
There was even criticism from some in the president's party, Morena, which holds strong majorities in both houses. The head of Mexico's National Migration Institute, Tonatiuh Guillen, resigned on Friday for "personal reasons", an interior ministry official said.
In the deal reached a week ago, Mexico also agreed to a plan that could make it a "safe third country" in which asylum seekers would have to seek refuge instead of in the United States, if Mexico does not bring down immigration flows by mid-July through enforcement measures. He will be replaced by prisons commissioner Francisco Garduno, the government said.