PHOENIX — Gov. Doug Ducey said Friday he has no knowledge of Arizona “bracing for a massive surge” of migrants through a “non-walled” part of the border after a warning by President Trump.

“We’re in constant communication with Homeland Security,” the governor said when asked about the president’s tweet, sent late Thursday night. “We’re working with them right now to understand what the situation is there.”

The president’s tweet said: “Arizona, together with our Military and Border Patrol, is bracing for a massive surge at a NON-WALLED area. WE WILL NOT LET THEM THROUGH. Big danger.”

It also said, “Nancy and Chuck must approve Boarder Security and the Wall,” misspelling the term “border” and referring to Democratic leaders Nancy Pelosi and Chuck Schumer.

Ducey said he had seen the tweet.

But as to its veracity, the governor had no specifics. In fact, he said, all the tweet did was raise more questions in his mind.

“I wanted to understand if there was a change in the situation,” Ducey said. “We want to get the facts.”

“Oftentimes the federal government will know, especially when it’s a coordination with the Department of Defense and Homeland Security, before the governor will know,” he said.

That, said Ducey, was the case earlier this year when there was a “surge” of migrants, with illegal entries up 200 percent over the prior year.

“It was the secretary of Homeland Security that came and shared that with me before that was in the public domain,” Ducey said.

What may have prompted the presidential tweet is a statement Tuesday by Customs and Border Protection that it had conducted a “joint large-scale operations readiness exercise” at the DeConcini Port of Entry in downtown Nogales, Arizona, along with the Department of Defense.

That exercise was noted by TV news along with video footage of a confrontation between some members of the caravan from Central America and border police that ended up with some migrants being teargassed as they sought to cross into the United States from Tijuana, Mexico.

The Nogales exercises, by contrast, was staged and controlled.

“They included tactical operations with the use of role players and inert smoke to simulate real-word environments,” a CBP statement said.

“This training will allow our officers to respond tactically should a situation arise,” it continued. “There were no impacts to port operations or the traveling public.”