“Right now, what is happening is the future [in Syria] is being decided by everybody but the United States ... and we are nowhere because American leadership has been withdrawn,” said Buttigieg, who was a U.S. Navy intelligence officer deployed to Afghanistan in 2014.

He also dismissed the notion of “completely” removing the U.S. military from the Middle East.

“We need to keep the American people safe when it comes to the Middle East,” Buttigieg said. “Yes, it will be messy for probably as long as I’m alive,” but the way to “end endless war” is not “saying ‘we're not even going to do anything until after we get attacked and are forced to get involved in some way.’”

"What President Trump does is wake up in the morning and have a phone call or, maybe, a tweet and completely change years or even decades of U.S. policy, surprising his own generals and country in the process,” Buttigieg said. “That's not how this works."

"The way to do it,” he added, “is to stay ahead of these problems, to engage our allies and to lead an international community to promote stability and peace."

Buttigieg also took issue on Sunday with Trump saying that Turkey had to have the Syrian border "cleaned out."

"My reaction is that those kinds of phrases have the darkest rhymes in world history," Buttigieg told Jake Tapper on CNN's “State of the Union.”

"We don't talk about cleaning out people, especially when there is an ethnic minority that has faced atrocities and appears to be facing crimes against humanity and atrocities, perhaps beginning right now."