FAYETTEVILLE, N.C. -- Appearing in a community heavily populated by military families, Democratic vice-presidential nominee Tim Kaine on Tuesday declared Donald Trump “unfit to be commander in chief,” accusing the Republican of having repeatedly spoken in a “thickheaded” and disrespectful way about U.S. troops.

Kaine, a senator from Virginia, took aim at Trump’s characterization during the Republican debates of the military as “a disaster,” arguing that was disrespectful rather than a signal that the GOP nominee wants to make the Armed Forces stronger.

“I don’t think in the history of the United States there has been a major party nominee who has talked with such disrespect about the military,” Kaine said. “We need a commander in chief who will not talk about them with contempt and disrespect, but will talk about them with respect and compassion and support. Anyone who says the American military is a disaster is unfit to be commander in chief.”

The Fayetteville area is home to Fort Bragg, the nation’s largest U.S. Army base, and North Carolina hosts several other military installations, including the Marine base of Camp Lejeune, where Kaine’s son was stationed until his recent deployment to Eastern Europe.

Kaine was making his second campaign stop in as many days in North Carolina, a battleground state that is widely considered must-win for Trump. On Monday, Kaine campaigned in Asheville.

Preparedness to be commander in chief has become a major issue in the presidential race, with both Hillary Clinton and Trump questioning the other’s fitness. On Monday, in a speech about fighting the Islamic State (also known as ISIS), Trump said Clinton “lacks the mental and physical stamina to take on ISIS and all of the many adversaries we face.”

Clinton, meanwhile, has touted the endorsements of a growing number of Republican military and national security figures who question Trump’s fitness to lead the nation.

During his remarks here Tuesday, Kaine also resurrected Trump’s comments from early in the campaign questioning whether Sen. John McCain (R-Ariz.) should be considered a war hero, given he was captured in Vietnam.

“How about making fun of John McCain for being a POW?” Kaine asked a racially diverse audience. “He said, 'I don’t consider him a hero because he got captured.' Could you be more thickheaded, insensitive or ignorant than that? It’s unbelievable that those words would come out of anybody’s mouth, much less the mouth of somebody who wants to be commander in chief.”

Kaine also cited Trump’s recent criticism of the Muslim family of a soldier killed in Iraq who spoke out against Trump at the Democratic National Convention.

“Go after a Gold Star family?” Kaine said. “That is not the kind of person we need in office.”