President Donald Trump said Sunday that additional details about the agreement reached with Mexico, which were not included in the immigration deal announced over the weekend, will be made public. 

"Importantly, some things not mentioned in yesterday press release, one in particular, were agreed upon," Trump said in a Twitter post. "That will be announced at the appropriate time."

The president did not provide any additional details. 

Trump expressed  "full confidence" in the deal negotiated with Mexico, in which the Mexican government agreed to stronger immigration enforcement in exchange for the U.S. not imposing tariffs on Mexican exports. 

Trump said he spoke with Mexico's president over the weekend, Andrés Manuel López Obrador, and he believes the Mexican government "will be very cooperative" and "get the job properly done." 

However, Trump said the U.S. could go back to its original position on tariffs if Mexico is not cooperative, but said he does not believe that will be necessary.

The president also took issue with a New York Times report, in which anonymous Mexican and U.S. officials told the paper that much of what was included in Friday's immigration deal had been agreed to months ago. 

Trump slammed the paper as the "enemy of the people."