Libertarian presidential candidate Gary Johnson went on the offensive over foreign policy Wednesday night, but not before drawing a blank on the names of just about every foreign leader alive today.

Even Johnson had to admit he was making a gaffe as he tried and failed to answer Chris Matthews' question on who his favorite foreign leader is, holding his head in his hand for seconds on a live episode of MSNBC's "Hardball," filmed at a town hall in the University of New Hampshire.

"I guess I'm having an Aleppo moment on the former president of Mexico," he said.

Johnson, the former governor of New Mexico, was referring to a blunder he made a few weeks ago on MSNBC's "Morning Joe," when he was asked what he would do about the situation in war-torn Aleppo in Syria.

"What is Aleppo?" he asked. Johnson later expressed frustration with himself and said, "I have to get smarter."

In Wednesday's gaffe, Johnson managed to identify "the former president of Mexico" as his favorite leader, but couldn't name which one. His running mate, ex-Massachusetts Gov. Bill Weld, chimed in with the name Vicente Fox, which Johnson said was correct.

Later in the Q&A, Johnson took a big swing at Hillary Clinton, saying he doesn't have confidence in her when it comes to nuclear weapons restraint.

Johnson insisted "she's gonna shoot" when Matthews asked if he thinks Clinton has a "happy trigger," going on to say he thought she would not want to be perceived as weak.

"Confronted with that 10 minutes, she's gonna be hawkish," he said.

Johnson is polling at 10 percent among likely voters, according to the latest NBC News/SurveyMonkey poll. He told Matthews he needs to start polling higher so that he'd be able to participate in the final two debates and have a shot at winning the presidency.