The 2008 GOP presidential nominee said he opposed sending combat troops back to Iraq, but added the U.S. can provide other kinds of aid, such as logistics support and Apache helicopters.

“I would suggest perhaps sending David Petraeus and Ambassador (Ryan) Crocker back over there,” McCain told CNN chief political correspondent Candy Crowley. “(Iraqi Prime Minister Nuri) Al-Maliki trusts them.”

Petraeus has largely stayed out of the limelight since he resigned from his post as CIA director in November 2012 following an affair with his biographer, Paula Broadwell.

Crocker was the U.S. ambassador to Iraq from 2007 to 2009, before becoming the ambassador to Afghanistan. He left the latter position in 2012 due to health reasons.