United States presidential nominee Gary Johnson has had a major foreign policy — and geography — stumble on network TV, as he failed to answer a basic question about the Syrian crisis.

The former New Mexico governor and nominee for the Libertarian Party was asked what he would do about the crisis in the war-torn city of Aleppo, Syria.

“What is Aleppo?” Mr. Johnson asked in all seriousness.

Watch Gary Johnson’s gaffe

“And what is Aleppo?” Gary Johnson asks https://t.co/po7gg7UPWi pic.twitter.com/FnMf65IN6o

— POLITICO (@politico) September 8, 2016

Interviewers didn’t seem convinced that Mr Johnson was serious, but when pressed on the question of the refugee crisis in Aleppo, he insisted he really didn’t know anything about the besieged city.

The interviewers had to come to Mr Johnson’s aid.

“O.K, got it,” Mr Johnson said

He went on to say that the US should partner with Russia to diplomatically improve the situation there.

“With regard to Syria, I do think that it’s a mess.”