Hillary Clinton has fond memories of traveling the world and drinking vodka shots with Senator John McCain.

That contest has become the stuff of political legends.

It took place in Tallinn, Estonia, in August 2004, when Clinton was a Democratic senator from New York traveling with McCain and other colleagues.

'We had fun and laughed a lot. We had some drinking associated with our fun,' she said on CNN Sunday morning.

Hillary Clinton recalled drinking vodka shots with John McCain during at 2004 trip to Tallinn, Estonia, where the two are pictured here

'What happens in Tallinn, stays in Tallinn,' she said

'We spent a memorable night in a hotel right on the old square doing vodka shots,' she said on CNN on Sunday.

She denied the drinking contest was her idea.

'I would not take credit for it. I think it was a mutually agreed upon venture but we used to say what happens in Tallinn, stays in Tallinn,' she laughed.

McCain recalled the trip in his final book 'The Restless Wave.'

'This was a trip that saw a pleasant evening's repast become an urban legend that recounted a vodka-drinking competition she and I are alleged to have had in Tallinn,' he wrote.

Clinton said it was a common act of McCain's to invite younger colleagues to travel with him on codels, the name for official trips senators take to other parts of the world.

'He liked to tryout different colleagues to see whether they were good traveling companions,' Clinton said on CNN. 'And I admit to being a little surprised when he first approached me and said would you like to travel? And I immediately said, sure, I think that would be quite an experience. And during those long long flights, we had a lot of time to talk. We talked about the unfairness that sometimes infects our politics.'

Clinton has spoken of their vodka drinking contest on previous occasions.

In December 2015, when she was running for the presidential nomination, she posted a video to her Facebook page where she talked about drinking with the senator.

Clinton and McCain took several trips together when they were senators including this August 2004 trip to Norway

Hillary Clinton and John McCain at a Senate Foreign Relations Committee hearing in 2013

She said no winner was declared.

'We both I think agreed to withdraw in honorable fashion I think after having reached the limits that either of us should have had,' she said.

After that trip, McCain was reported to have called Clinton 'One of the guys.'

That wasn't the only memorable trip they took together.

In February 2005, they made a joint journey to Iraq and appeared on NBC's 'Meet the Press' together via satellite to talk about the trip.

When Tim Russert, then moderator of the show, asked McCain at the end of the interview if he thought Clinton would make a good president, she came to McCain's rescue.

THIS MORNING: A look back at some of Senator John McCain's best moments on Meet the Press. He was the show's most frequent guest, appearing 73 times. #MTP pic.twitter.com/KQExC9euGf — Meet the Press (@MeetThePress) August 26, 2018

Clinton also talked about the 2008 presidential contest where she lost the Democratic nomination but McCain was the Republican nominee

'Oh, we can't hear you, Tim,' she said.

'Yeah, you're breaking up,' McCain added, laughing.

But then he said: 'I happen to be a Republican and would support, obviously, a Republican nominee, but I have no doubt that Senator Clinton would make a good president.'

Asked the same question about him, Clinton replied: 'Absolutely.'

Clinton, a Democrat, and McCain, a Republican, formed a cordial relationship when both served in the Senate - a fact that became remarked upon when they ran for their parties' respective presidential nominations in 2008.

McCain went on to be the GOP nominee while Clinton lost the Democratic nomination to Barack Obama, who defeated McCain in the general election.

'I thought it would have been a great campaign because we both respected each other and worked with each other,' Clinton said on Sunday on CNN.

And she said she'd like to toast McCain soon with some vodka.

'I hope, I hope that will happen at some point in the future,' she said on NBC's 'Meet the Press.'