WASHINGTON – Undeterred by growing Republican criticism, President Donald Trump delivered an extended attack Wednesday on the late Sen. John McCain over longstanding disputes between the two men ranging from health care to foreign policy.

"I have to be honest, I never liked him much," Trump said during a speech at a military tank plant in Lima, Ohio, that was focused on the economy. "I probably never will."

The crowd, which included members of the military, remained largely silent during the remarks. Trump has ratcheted up his criticism of the Republican Arizona senator and Vietnam veteran and POW several times this week, but his remarks in Ohio brought up a litany of grievances from Trump that included the ceremonies to honor McCain after he died last year at 81.

"I endorsed him at his request and I gave him the kind of funeral that he wanted, which as president I had to approve," Trump said. "I don't care about this, I didn’t get 'thank you.' That’s OK."

The president, speaking on the McCain family last year, told Bloomberg News he did "everything that they requested." Trump allowed one of the planes used as Air Force Two to carry McCain's body to Washington for services. Trump did not attend McCain's funeral at the family's request.

Trump began hitting McCain on Sunday over the senator's decision to turn a Russian dossier over to the FBI. Trump said Wednesday that he continued to speak about the senator because the news media kept asking him about it.

"Not my kind of guy," Trump said, "But some people like him, and I think that's great."

Before Trump's latest riff, Sen. Johnny Isakson, R-Ga., criticized Trump for scorning McCain some seven months after the death of the senator the Republicans nominated for president in 2008. McCain, a Navy pilot, spent five and a half years as a prisoner of war in Vietnam before his release in 1973.

McCain died in August after battling brain cancer.

“It’s deplorable what he said, it will be deplorable if he says it again,” Isakson told the Georgia Public Radio program “Political Rewind.”

Wednesday's trip was the first of two trips Trump is making this month to Midwestern battleground states. The president, who is scheduled to hold a rally in Michigan next week, spent most of his Ohio address touting the nation's economy and low unemployment.

As Trump talked up success seen in some quarters of the nation's economy, he continued to face questions about the iconic General Motors plant in Lordstown, Ohio, which the automaker announced last fall would close this month. Trump launched a Twitter feud with GM this week, calling on the company to reopen the facility.

During his remarks Wednesday, Trump drew a distinction between union leaders and rank-and-file labor members whose support he may need to get re-elected. Trump told the crowd he likes union workers, but not their leaders.

“The heads of the union are not honest people,” the president said. “They are not honest.”

“And they ought to lower your dues,” he added. “You’re paying too much dues.”

Trump tailored much of his 2016 message to blue-collar manufacturing workers in the Rust Belt, helping him to flip states like Pennsylvania, Ohio, Michigan and Wisconsin from blue to red. Though there have been some gains in manufacturing in his first term, Trump also has faced a number of high-profile setbacks such as Lordstown.

U.S. manufacturing jobs have been steadily increasing since 2010 but are still well below the peak reached in the 1970s. There were 12.8 million U.S. manufacturing jobs in February, according to Department of Labor data, up from 11.4 million in 2010. There were more than 19.5 million manufacturing jobs in 1979.

Ohio bound:Trump drops into Ohio amid feud over iconic GM plant in Lordstown

After touring the tank plant in Lima, Trump said he thought about getting in one of the tanks but decided against it when he remembered what happened to Michael Dukakis, the 1988 Democratic presidential nominee.

Dukakis, then the governor of Massachusetts, was ridiculed mercilessly when he put on a helmet and rode in a tank at an event in Michigan. The photo op was intended to demonstrate Dukakis could be a worthy commander in chief but backfired so badly that many politicians ever since have refused to don headgear of any kind.

“He tanked when he got into the tank,” said Trump, who regularly sports a baseball cap with his Make America Great Again campaign slogan. “The helmet was bigger than he was.”