President Trump offered the full resources of the federal government to assist Mexico with their cartel crisis, but Mexican President Andrés Manuel López Obrador rebuffed his offer and remains unmoved, said White House counselor Kellyanne Conway on Wednesday.

Conway appeared on "Fox & Friends" to discuss the brutal murder of nine U.S. citizens, who were gunned down in Mexico on Monday after being caught in the crossfire of suspected cartel gunmen. The victims ranged in age from 8 months to 43 years old, with some being burned alive.

"The president said to the Mexican president, 'We've got to go after these cartels.' And the Mexican president didn’t seem persuaded," she said.

"[Trump] will continue to ensure the safety and well being of Americans, including, if not especially, innocent children, wherever they are. This president has made a priority -- a centerpiece -- of his administration stopping the flow of drugs over our borders," Conway added.

RELATIVE OF AMERICANS KILLED IN MEXICO BELIEVES FAMILY WAS USED AS 'BAIT' IN CARTEL WAR OVER SMUGGLING ROUTES

She said Trump will stop at nothing to help eradicate the sociopathic elements within the drug cartels that seek to harm America and its citizens.

"This president will continue to press the issue," she said. "I work on the drug crisis here... It is a very serious problem, what's coming over the southern border and what’s going on with the cartels.

"They are ruthless. They are fearless. And they are very savvy business people in that, they don’t care who gets in their way and in the way of their profits."

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Investigators early Wednesday said a suspect in the slayings was arrested near the Arizona border with Mexico. The Agency for Criminal Investigation said in a statement on Facebook the suspect was found in the town of Agua Prieta, right across the border from Douglas, Arizona. The suspect was holding two hostages who were bound and gagged inside a vehicle.

Investigators found four assault rifles and a bulletproof SUV.