Mexican President Claudia Sheinbaum said Wednesday that Mexico sent 37 cartel members to United States at the request of the Justice Department, but insisted it was a “sovereign decision” by Mexico.

Sheinbaum responded to claims by analysts and opponents who said the transfers carried out the previous day were the result of mounting pressure from Washington as President Donald Trump has threatened to take military action on cartels.

Speaking at her regular morning news briefing, Sheinbaum said that although the transfers were made at the request of the U.S. government, the decision was taken by the National Security Council after analyzing what was “convenient for Mexico” and in terms of its “national security.”

“Mexico is put first above all else, even if they ask for whatever they have to ask for. It is a sovereign decision,” she added.

Sheinbaum, who has been praised for her level-headed management of relations with Trump, has been forced to walk a fine line between making concessions to the U.S. government and projecting strength both domestically and internationally.

Observers say the Mexican government has used the transfers as a sort of pressure valve to offset demands by Trump and show authorities are cracking down on criminal groups. Tension has only mounted since the U.S. carried out a military operation in Venezuela and deposed of then-President Nicolás Maduro in an extraordinary use of force that set leaders across Latin America on edge.

The Justice Department on Wednesday said in a statement to the Associated Press said that Mexico working with the U.S. was in the mutual interest of both countries.

“This is an important step taken by Mexican authorities and we look forward to continuing to work with them in the protection and defense of our region,” the statement added.

Those sent to the U.S. on Tuesday were alleged members of the powerful Jalisco New Generation Cartel and Sinaloa Cartel, which Washington has designated as terrorist organizations, and a number of other groups. It’s the third such transfer of capos over the past year. Mexico’s government said it has sent 92 people in total to the U.S. in total.

In August, Mexico’s security minister acknowledged that some of the cartel leaders sent to the United States at that time were continuing criminal operations from prison and that their transfer was agreed upon because there was a risk they could be released due to judicial rulings.