Washington (CNN) Sen. Johnny Isakson said President Donald Trump's criticism of the late Sen. John McCain is "deplorable," and the Georgia Republican promised to continue speaking out against Trump if he continues to speak ill of the deceased war hero and former GOP presidential nominee.

"It's deplorable what he said," Isakson told Georgia Public Broadcasting on Wednesday afternoon when asked about a series of critical comments Trump has made about McCain. "That's what I said on the floor of the Senate seven months ago. It will be deplorable seven months from now if he says it again and I will continue to speak out."

Isakson continued "There aren't Democratic causalities and Republican casualties on the battlefield, there are American casualties. And we should never reduce the service that people give to this country including the offering of their own lives to any political fodder in Washington, DC, or anywhere else for that matter."

In the wake of McCain's death last year, Isakson gave a Senate speech at the time that said "anybody who in any way tarnishes the reputation of John McCain deserves a whipping because most of those who would do the wrong thing about John McCain didn't have the guts to do the right thing when it was their turn."

Isakson told the station Wednesday, "we can't talk about our veterans in any way but to thank them for the service they render for the job that they do."

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