Mexican President Andrés Manuel López Obrador on Tuesday swiftly rejected an offer from U.S. President Donald Trump to send American troops over the border to "wage war" on drug cartels after assailants killed at least nine members of a fundamentalist Mormon family in northern Mexico.

During a press conference Tuesday, López Obrador, commonly known as AMLO, thanked Trump and "any foreign government which wants to help" in the aftermath of the gruesome killing of dual U.S.-Mexican citizens, which authorities believe was carried out by cartel members.

"Active U.S. support for the drug war in Mexico has been the status quo for more than a decade—it has fueled one of the deadliest conflicts in the western hemisphere and destabilized whole regions of the country."

—Ryan Devereaux, The Intercept

"But in these cases," AMLO said, "we have to act independently and according to our constitution, and in line with our tradition of independence and sovereignty."

"War is irrational," the Mexican president added. "We are for peace."

AMLO's comments came after Trump fired off a series of tweets Tuesday morning offering Mexico "help in cleaning out these monsters."

"The great new President of Mexico has made this a big issue, but the cartels have become so large and powerful that you sometimes need an army to defeat an army!" Trump said. "This is the time for Mexico, with the help of the United States, to wage WAR on the drug cartels and wipe them off the face of the earth. We merely await a call from your great new president!"

A wonderful family and friends from Utah got caught between two vicious drug cartels, who were shooting at each other, with the result being many great American people killed, including young children, and some missing. If Mexico needs or requests help in cleaning out these..... — Donald J. Trump (@realDonaldTrump) November 5, 2019 ....monsters, the United States stands ready, willing & able to get involved and do the job quickly and effectively. The great new President of Mexico has made this a big issue, but the cartels have become so large and powerful that you sometimes need an army to defeat an army! — Donald J. Trump (@realDonaldTrump) November 5, 2019

In response to Trump's tweets Rep. Don Beyer (D-Va.) wrote sarcastically, "Nothing says you're 'against endless wars' like announcing that you want to send U.S. troops 'to wage WAR' in Mexico."

The Intercept's Ryan Devereaux noted that the U.S. has been helping Mexico wage a war on drugs for years—with disastrous consequences.

"Active U.S. support for the drug war in Mexico has been the status quo for more than a decade—it has fueled one of the deadliest conflicts in the western hemisphere and destabilized whole regions of the country," said Devereaux.