Mexican President Andres Manuel Lopez Obrador on Thursday rebuked calls from some US lawmakers advocating military action in Mexico against drug cartels, describing the proposals as threats to Mexican sovereignty.
"We are not going to permit any foreign government to intervene in our territory, much less that a government's armed forces intervene," Lopez Obrador said during a regular news conference.
The kidnapping of four Americans - two of whom were killed - in a northern border state intensified calls from Republican lawmakers in Washington to take a tougher line on organised crime.
Texas Republican Dan Crenshaw on Wednesday released a message in Spanish on Twitter asking Lopez Obrador why he opposes a proposal the congressman introduced in January authorising military force targeting drug cartels in Mexico.
"In addition to being irresponsible, it is an offense to the people of Mexico," Lopez Obrador said during the news conference, adding that Mexico "does not take orders from anyone."
Republican Senator Lindsey Graham on Monday said in a Fox News interview that it was time to "put Mexico on notice" and advocated introducing legislation to classify some Mexican drug cartels as "foreign terrorist groups."
The fatal kidnappings and backlash could complicate delicate efforts to foster closer collaboration between the US and Mexico on immigration and the trafficking of drugs, particularly ultra-lethal fentanyl.
Lopez Obrador said he would begin a public information campaign aimed at Mexicans in the US about the Republican-led proposal.
If Republican lawmakers try to "use Mexico for their propagandist, electoral and political purposes, we will make a call to not vote for that party," Lopez Obrador said.