FILE - Retired U.S. General Stanley McChrystal speaks during an event in Washington, D.C., Dec. 2, 2014.
FILE - Retired U.S. General Stanley McChrystal speaks during an event in Washington, D.C., Dec. 2, 2014.

Retired U.S. Army General Stanley McChrystal blasted U.S. President Donald Trump, calling him dishonest and immoral.

The former commander of U.S. troops in Afghanistan told ABC's This Week news show, "I don't think he tells the truth."

Responding to Trump's announcement that he will withdraw half of all U.S. troops deployed in Afghanistan, McChrystal said the move would reduce the incentive for the Taliban to negotiate a peace deal after more than 17 years of war.

He said, making the decision, Trump has "basically traded away the biggest leverage point we have.''

"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,'' McChrystal said.

He was also highly critical of the president's personal character. When asked if Trump is immoral, McChrystal responded: "I think he is.''

This is not the first time McChrystal has slammed a sitting president. He was forced to resign in 2010 after he criticized the Obama administration in an article in Rolling Stone magazine.