Secretary of State Mike Pompeo said Monday that the U.S. and Mexico will know within 45 days whether the new border security deal the two countries hashed out is working.

He also discounted reports that there wasn’t much new in the deal, saying the declaration he and the Mexican foreign ministry announced late Friday is “fundamentally different” than anything the two sides had reached before.

Mr. Pompeo, speaking to reporters at the State Department, said the pressure is now on the U.S. and Mexico to make the agreement work in reducing the numbers of people streaming north from Central American, crossing Mexico and hoping to breach the U.S. border.

“We will evaluate this literally daily,” the secretary said, calling the declaration “a significant win.”

He echoed Mexico’s ambassador to the U.S., who on Sunday said they would like to see results “in a very relative short term, like in a month or a month and a half.” Mr. Pompeo said “perhaps a month, perhaps 45 days, we’ll have a good sense.”

Mexico did agree to deploy some 6,000 new national police to enhance security in its own southern border region — including policing illegal immigration.

Mexico also agreed to expand its cooperation with the Trump administration’s Migration Protection Protocol (MPP), the so-called “remain-in-Mexico” policy, under which the U.S. government is taking Central American asylum-seekers who crossed Mexico and returning them to Mexico to wait while their asylum cases are heard in American immigration courts.

“We now have the capacity to do this full-throttle,” Mr. Pompeo said Monday.

The goal is to change the incentive structure. The Central Americans generally want to reach the U.S. and make asylum claims as a way of gaining a foothold. Few will actually qualify, but once on U.S. soil they can disappear into the shadows.

If they are made to wait in Mexico, U.S. officials hope they lose the incentive to try the journey in the first place.

A smaller version of the MPP has been in effect for months, but under the new deal Mexico agreed to expand its cooperation border-wide. It will offer work permits, health care and humanitarian assistance to the migrants who get returned to its territory to wait.

The U.S., for its part, agreed to speed up hearing asylum cases in U.S. immigration courts.