Donald J. Trump found himself on the defensive on Sunday over his claims that he had opposed the intervention in Libya and the war in Iraq.

Mr. Trump has described himself in the presidential campaign as an ardent detractor of both interventions, but his critics cite evidence to the contrary.

In an interview on CBS’s “Face the Nation,” the host, John Dickerson, pointed out that Mr. Trump had supported military intervention in Libya and the ouster of its leader, Col. Muammar el-Qaddafi, despite the fact he now criticizes Hillary Clinton on both points.

“When you say supported it, I supported Libya?” Mr. Trump said.

“Yes, you supported the intervention in Libya,” Mr. Dickerson replied.