DENVER (AP) — If it was greater attention Libertarian presidential candidate Gary Johnson wanted, he got it — but probably not the kind he wanted.

As part of a media blitz in New York to try to raise his polling numbers enough to qualify for the upcoming presidential debates, Johnson fielded a range of questions Thursday with the aim of demonstrating he can take on Hillary Clinton and Donald Trump.

But one stumped him.

“What would you do about Aleppo?” Johnson was asked on MSNBC’s “Morning Joe,” a question about Syria’s largest city, which has been engulfed by the country’s ongoing civil war.

“What is Aleppo?” Johnson responded.

Syria’s 2011 pro-democracy uprising, which gradually devolved into civil war, has sparked a refugee crisis across the Middle East and Europe as millions fled their homes for safety.

When reminded of those facts by MSNBC on Thursday, Johnson said he’d work with Russia to find a diplomatic solution to the civil war and that the conflict was an example of the dangers of meddling in the region.

Johnson’s blunder sparked widespread mockery, with a #WhatisAleppo hashtag trending on Twitter. Clinton chucked at a news conference when asked about Johnson’s flub.

“You can find Aleppo on a map,” she said.

Johnson later acknowledged to another MSNBC reporter the attention to the error was deserved and apologized in a statement, saying he was thinking of an acronym, not the Syrian city.

“I blanked,” he said. “It happens, and it will happen again during the course of this campaign.”

He added, “Can I name every city in Syria? No. Should I have identified Aleppo? Yes. Do I understand its significance? Yes.”

The error couldn’t have come at a worse time for Johnson. He needs to average 15 percent in a set of polls to qualify for the presidential debates, the first of which is Sept. 26. He picked up high-profile support Wednesday night when former Republican presidential nominee Mitt Romney tweeted that Johnson should be allowed in the debates.

Johnson seemed to recognize the peril of the Aleppo error. In a subsequent interview on ABC’s “The View,” he said: “For those that believe this is a disqualifier, so be it.”