Speaking at a Democratic party event in Ohio, Biden told his audience:
"Do you know what I just had to do? I had to change my schedule to get in a plane to fly to Latvia, Estonia and Lithuania. You know why? To meet with the presidents... to reassure them that Donald Trump didn't represent America.
"Because do you know what Donald Trump said? Donald Trump said he's not sure he'd honor our NATO commitment to protect them if Russia invaded them."
"They're scared to death, with good reason, that Russia will cross the border and annex them like they did Crimea.
"And what does Donald Trump say? These are members of NATO. He says we're going to check whether they've paid all their dues. He's causing - for the first time, with Bush or Clinton or Obama - for the first time he's causing nations to wonder whether we'll keep our word."
"The idea that I would get on a plane to make, basically an emergency flight, to hold the hands of three presidents from Estonia, Latvia and Lithuania and say: 'No no no, he doesn't represent Republicans or Democrats on this, don't worry...' This the guy who admires Putin? This is the guy who doesn;t know Russian troops have already come across the border and annexed Crimea?"
"He has no idea what he's talking about," Biden said, before adding "that's okay sometimes... but imagine giving this guy access to the nuclear codes."
You can see Biden's speech below, with his Baltic comments starting at 31 minutes and 7 seconds.