Donald Trump has said Hillary Clinton’s foreign policy plan in Syria would trigger World War Three.
The Republican also said the US should focus on defeating ISIS rather than removing Syria’s president.
Hillary Clinton has proposed a no-fly zone over Syria. The top US military chief has said that could spell conflict with Russian jets in the region.
The Clinton campaign accused Donald Trump of “playing to Americans’ fears”.
The New York billionaire also attacked Republicans for not uniting behind his candidacy.
“If we had party unity, we couldn’t lose this election to Hillary Clinton,” Donald Trump told Reuters at Trump National Doral golf resort in Miami, Florida.
He struck an apocalyptic tone when criticizing his Democratic rival’s plan to control Syrian air space.
“You’re going to end up in World War Three over Syria if we listen to Hillary Clinton,” he said.
“You’re not fighting Syria anymore, you’re fighting Syria, Russia and Iran, all right?
“Russia is a nuclear country, but a country where the nukes work as opposed to other countries that talk.”
Donald Trump suggested there should be a refocus away from the long-held US position of trying to remove Syrian President Bashar al-Assad, saying: “What we should do is focus on IS. We should not be focusing on Syria.”
He also suggested Hillary Clinton would be unable to talk with Russian President Vladimir Putin after her sharp criticism of him.
Donald Trump questioned “how she is going to go back and negotiate with this man who she has made to be so evil” if she is elected president on November 8.
The Clinton campaign dismissed the criticism, saying both Republican and Democratic national security experts have denounced Donald Trump as unfit to be commander-in-chief.
“Once again, he is parroting Putin’s talking points and playing to Americans’ fears, all while refusing to lay out any plans of his own for defeating ISIS or alleviating humanitarian suffering in Syria,” Hillary Clinton spokesman Jesse Lehrich said in a statement.
Donald Trump’s warning of confrontation with Russia echoes concerns raised last month at a congressional hearing by the highest-ranking military officer in the US armed forces.
Chairman of the Joint Chiefs Marine General Joseph Dunford told lawmakers a “no-fly zone” in Syria could spell war with Russia.
“Right now, senator, for us to control all of the airspace in Syria it would require us to go to war, against Syria and Russia,” he told the Senate Arms Services Committee.
“That’s a pretty fundamental decision that certainly I’m not going to make.”
At the final presidential debate in Nevada on October 19, Hillary Clinton outlined her support for the measure.
“A no-fly zone can save lives and hasten the end of the conflict,” she said on stage.
However, in a 2013 speech to Goldman Sachs, Hillary Clinton said establishing a no-fly zone would “kill a lot of Syrians”, according to a transcript disclosed by WikiLeaks.