President Donald Trump speaks Wednesday to the “Rx Drug Abuse and Heroin Summit,” in Atlanta.

WASHINGTON • President Donald Trump renewed his threat Wednesday to send more troops to the U.S.-Mexico border after an incident in which Mexican soldiers confronted U.S. personnel. Mexico blamed the incident on confusion, and said it was not looking for confrontation with the U.S.

In morning tweets, Trump said, “Mexico’s Soldiers recently pulled guns on our National Guard Soldiers,” claiming, without evidence, that it was done “probably as a diversionary tactic for drug smugglers on the Border.”

“Better not happen again!” he added. “We are now sending ARMED SOLDIERS to the Border. Mexico is not doing nearly enough in apprehending & returning!”

Trump last year dispatched U.S. troops to the border to assist border personnel in response to several caravans of Central American migrants traveling through Mexico in hopes of reaching the U.S. Many are already armed.

This month, two U.S. soldiers in a remote area of Texas were confronted by Mexican soldiers who thought the Americans had crossed into Mexico.

The Mexican troops reportedly removed a weapon from one of the American soldiers. U.S. Northern Command, which manages military support for Customs and Border Protection, said the Americans were in a Customs and Border Protection vehicle in a remote area of U.S. territory south of the border wall but north of the actual border.

“After a brief discussion between the soldiers from the two nations, the Mexican military members departed the area,” Northern Command said in a statement about the encounter.

Mexican President Andrés Manuel López Obrador promised to investigate the incident at a Wednesday news conference.

“We are not going to fight with the government of the United States,” he said. “The most important thing is that we want a relationship of mutual respect and cooperation for development.”

Mexico’s foreign relations department characterized the incident as “routine” confusion in an area where the line separating the two countries is unclear.

While not every U.S. service member deployed to the border is armed, many — including those performing the “mobile surveillance camera” mission, like the two confronted by the Mexican soldiers — are armed for self-protection.