Secretary of State Mike Pompeo Monday reiterated President Trump’s assertion that the U.S.’s recent deal with Mexico regarding immigration and the border was a success – arguing that the agreement moves beyond just ramping up existing efforts by the two nations.

Calling the agreement “diplomacy at its finest” and a “win for the American people,” Pompeo balked at criticism from both Trump administration opponents and some in the media that little, if any, headway was made during the meeting.

“I’ve seen some reporting that these negotiations were a waste of time,” Pompeo said during a press briefing. “The scale, effort, cooperation is very different from what was discussed in November.”

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While the U.S. and Mexico reached a tentative deal about asylum-seekers hoping to enter the U.S. last year, the Trump administration believed Mexico was not holding up its end of the bargain and the president threatened to levy major tariffs on Mexican goods as a way to bring them to the negotiating table.

Pompeo on Monday would not go into specifics about what new measures Mexico agreed to during the recent talks, aside from saying that it agreed to send an additional 6,000 Mexican National Guard troops to the border in an effort to deter migrants from entering the U.S. illegally.

The Secretary of State added that Washington would be keeping a close watch to make sure Mexico adheres to the stipulations of the agreement and echoed Trump in saying that tariffs could once again be enacted if Mexico fails to live up to the terms.

“We will evaluate this literally daily,” Pompeo added.

Pompeo’s comments came hours after Trump tweeted on Monday morning that Mexico had agreed to action beyond what was outlined in the Friday announcement and said that more would be revealed soon. Mexican Foreign Secretary Marcelo Ebrard, however, said there was no secret deal was in the works.

The president has pushed back on criticism about just how much of the deal with Mexico is actually new.

The deal included a commitment from Mexico, for instance, to deploy its new National Guard to the country's southern border with Guatemala. Mexico, however, had already intended to do that before Trump's latest threat and had made that clear to U.S. officials. Mexican officials have described their commitment as an accelerated deployment.

The U.S. also hailed Mexico's agreement to embrace the expansion of a program implemented earlier this year under which some asylum seekers are returned to Mexico as they wait out their cases. But U.S. officials had already been working to expand the program, which has already led to the return of about 10,000 to Mexico without Mexico's public embrace.

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Trump has pushed back on that criticism, defending the deal and his threat to slap a five percent tax on all Mexican goods Monday to pressure the country to do more to stem the flow of Central American migrants across the U.S. southern border. Without the threat, he has insisted, Mexico never would have acted.

Acting Homeland Security Secretary Kevin McAleenan, speaking on "Fox News Sunday," also insisted "all of it is new," including the agreement to dispatch around 6,000 National Guard troops — a move Mexico has described as an "acceleration."

"This is the first time we've heard anything like this kind of number of law enforcement being deployed in Mexico to address migration, not just at the southern border but also on the transportation routes to the northern border and in coordinated patrols in key areas along our southwest border," he said, adding that "people can disagree with the tactics" but that "Mexico came to the table with real proposals" that will be effective, if implemented.

The Associated Press contributed to this report.