Retired four-star Army Gen. Stanley McChrystal sharply criticized President Donald Trump in an interview Sunday, saying he does not think the president is moral or honest.

The former commander of U.S. and international forces in Afghanistan – whom former President Barack Obama removed for comments criticizing his administration in Rolling Stone magazine – told ABC’s “This Week” host Martha Raddatz that, if asked, he would not serve in Trump’s administration.

"I think it's important for me to work for people who I think are basically honest, who tell the truth as best they know it," McChrystal said.

“You think he’s a liar?” Raddatz asked.

"I don't think he tells the truth," McChrystal replied.

"Is Trump immoral, in your view?" Raddatz then asked.

"I think he is," McChrystal said.

McChrystal said he "can't tell any supporter of one politician or another that they are wrong." But he asked Americans to look in the mirror and ask themselves if they are willing to ignore the "unacceptable" things Trump does "just because they accomplish certain other things that we might like."

He said that Trump is so "shady" that he wouldn't want to do a business deal with him and that a willingness to be governed by such a man is "in conflict with who I think we are."

McChrystal also rebuked Trump for attacking Democrats and pushing for a border wall in his address to U.S. troops during a surprise visit to Iraq last week.

"When leaders visit soldiers, young women and men out in potentially harm's way, there's a sacred interaction that occurs," McChrystal told Raddatz. "You're also listening to their problems. You don't use that as a time to tout your politics or your personal opinions."

He also said that images of troops presenting Trump with red "Make America Great Again" hats was "unfortunate" because "if the U.S. military becomes politicized, it will be something we're not happy with."

McChrystal said Trump's plan to begin drawing down the U.S. troop presence in Afghanistan is a "mistake."

"Just when we were starting to sit down with the Taliban, just when we were starting to begin negotiations, he basically traded away the biggest leverage point we have," he said.

"If you tell the Taliban that we are absolutely leaving on date certain, cutting down, weakening ourselves, their incentives to try to cut a deal drop dramatically," he added, ironically echoing a criticism Trump routinely made of Obama's announced troop withdrawal from Iraq.