WASHINGTON (Reuters) - U.S. President Donald Trump defended his administration’s deal with Mexico against criticism that there were no major new commitments to stem a flow of Central American migrants crossing into the United States, and said on Sunday more details would soon be released.

Key aspects of the agreement are still unclear, including whether Mexico has pledged to buy more U.S. agricultural products and if the deal materially expanded a previous commitment by Mexico to more vigorously police its southern border with Guatemala.

Top Democratic senators said many aspects of the deal were not new, while the Mexican ambassador to the United States declined to confirm whether it contained any commitments on agricultural goods.

The deal, announced on Friday after three days of talks in Washington, averted Trump’s threatened imposition of 5% import tariffs on all Mexican goods that had been due to start on Monday unless Mexico committed to do more to help reduce an increase in migrants arriving at the U.S. southern border.

“Mexico was not being cooperative on the Border...and now I have full confidence, especially after speaking to their President yesterday, that they will be very cooperative and want to get the job properly done,” Trump said on Twitter.

“Importantly, some things not mentioned in yesterday press release, one in particular, were agreed upon. That will be announced at the appropriate time,” he added.

Trump did not elaborate and the White House and State Department did not immediately respond to requests for comment.

Friday’s joint communique broadly sketched the terms of the agreement, but contained few details.

The Mexican peso jumped against the dollar in Asian markets and U.S. equity futures rose on Sunday following the deal.

FILE PHOTO: U.S. President Donald Trump talks about the U.S.-Mexico border during a fundraising roundtable with campaign donors in San Antonio, Texas, U.S. April 10, 2019. REUTERS/Carlos Barria

The agreement expedites a program known as the Migration Protection Protocols that was announced in December. That program sends migrants seeking asylum in the United States to wait in Mexico while their cases are being processed.

Friday’s agreement would see the United States immediately expand the implementation of the MPP across its entire 2,000-mile (3,220-km) southern border, the State Department said on Friday.

But as of Sunday night, U.S.-bound asylum seekers were not yet being sent back to additional Mexican border towns, three Mexican officials said.

Officials in the Mexican border states of Sonora, south of the U.S. states of Arizona and New Mexico, and Tamaulipas, south of Texas, said they were unaware of plans to expand the number of border crossings where the asylum seekers must be returned to Mexican territory to await processing.

The deal will also see Mexico deploy the National Guard police force to its southern border, where many Central American migrants enter Mexico.

UNCERTAINTY OVER AGRICULTURE

On Saturday, a New York Times report, citing officials from both countries familiar with the negotiations, said most of Friday’s deal had already been sketched out in March, when Mexico agreed to deploy its National Guard throughout the country, with priority given to the southern border.

Trump tweeted on Sunday that the Times report was false, adding: “We have been trying to get some of these Border Actions for a long time, as have other administrations, but were not able to get them, or get them in full, until our signed agreement with Mexico.”

But it was business as usual over the weekend at the busiest crossing point along Mexico’s porous southern border with Guatemala. Evidence of Mexico’s promised crackdown on new arrivals trying to reach the United States was nowhere to be seen, as a small fleet of rafts carried migrants hoping to escape the violence of Central America.

Senate Democratic leader Chuck Schumer also said there appeared to be little new in the deal, adding it was a “bogus” solution used by Trump to get out of an ill-conceived tariff threat.

“This is likely to have only a small impact on solving the root causes of Central American migration because many of the components are things Mexico had already said they would do,” Schumer said on Twitter.

U.S. Vice President Mike Pence said on Twitter, however, that Trump’s “strong stand got Mexico to do things they have never done before.”

There is further uncertainty around Trump’s comments on Saturday that Mexico had agreed to “immediately begin” buying “large quantities” of agricultural goods from U.S. farmers.

Mexican officials have not confirmed any new agreement on agricultural products. Asked repeatedly about such a deal on CBS on Sunday, the Mexican ambassador to the United States, Martha Bárcena Coqui, said only that trade would increase without the tariffs. She said there were many details discussed during negotiations that were not in the written declaration.

She noted Mexico was already a top U.S. trade partner in agricultural products. Mexico is the top importer of U.S. corn, wheat, pork and dairy by volume.

On Saturday, Mexico’s foreign minister, Marcelo Ebrard, tweeted that the deal should boost economic growth and therefore demand for U.S. agricultural products, but he also stopped short of saying that the deal contained a commitment on Mexico’s part to purchase more goods from the United States.