The deal the U.S. and Mexico struck to prevent the U.S. from imposing tariffs largely reaffirms the countries’ commitments to existing measures on immigration but will allow Washington to keep up pressure on Mexico.

The deal reached late Friday included a provision that former diplomats and analysts said reinforces the idea that the U.S. will continue to use tariffs as leverage: The U.S. will review the effectiveness of Mexico’s immigration policies after 90 days.

“Unless...