Mexican President Claudia Sheinbaum on Monday urged the United States to take stronger action to curb drug and arms trafficking across the border, amid growing tensions over Washington's threat to impose new tariffs on Mexico.

In a letter to Sheinbaum on Saturday, U.S. President Donald Trump threatened to implement a 30-percent tariff on Mexican imports starting August 1, accusing Mexico of failing to stop drug trafficking and illegal immigration into the U.S.

Sheinbaum on Monday hit back at the criticism, calling on the U.S. to redouble its efforts to curb drug and arms trafficking on its own turf.

"We do our part and they also have to do their part," she said at her daily press conference."There is collaboration. There is coordination."

Sheinbaum noted she hopes to reach a deal with the U.S. to avoid Trump's proposed 30 percent tariff.

"We believe ... that we will reach an agreement with the U.S. government – and that we will, of course, reach better terms," Sheinbaum said.

Mexico sent a government delegation to the U.S. on Friday to begin talks with Washington on trade, energy, immigration and crime.

Sheinbaum said she would meet later in the day with Economy Secretary Marcelo Ebrard and other officials involved in the negotiations. She emphasized that any agreement with Washington must be grounded in respect for Mexico's sovereignty, calling it a "non-negotiable principle."