The US military announced on Saturday that it was sending the USS Gravely, a guided-missile destroyer, to the Gulf of Mexico to help protect US "territorial integrity" and security.

The Mexican government was informed before the vessel departed, Sheinbaum told a news conference.

"It's not against Mexico," she said.

"They're monitoring international waters in case of drugs or any other situation," she added.

Sheinbaum has repeatedly voiced opposition to potential military action against drug trafficking groups designated terrorist organizations by US President Donald Trump, who has vowed to wage war on the cartels.

Her government has pledged to collaborate with Washington on tackling trafficking of fentanyl and other drugs.

In return for Sheinbaum deploying 10,000 extra soldiers to the frontier to border with the United States, Trump last month agreed to suspend 25 percent tariffs on Mexican goods.

He later granted Mexico another month of temporary tariff relief after speaking with Sheinbaum, who made the case that Mexican drug seizures had led to a sharp drop in cross-border fentanyl flows.