Former Secretary of State Hillary Clinton said she will support Sen. Bernie Sanders, I-Vt., if he wins the Democratic presidential nomination, but she did not commit to campaigning on his behalf. 

Clinton weighed in on the 2020 Democratic race in an interview with CNN's Fareed Zakaria that aired Sunday. Her comments come amid an increasingly tense race between Sanders and former Vice President Joe Biden for the party's nomination to face President Donald Trump in November.

"I will support the nominee of the Democratic Party," Clinton said when asked whether she would campaign for Sanders. Pressed again, she suggested that the decision is up to Sanders.

"I don't know if he would ask me to campaign for him, Fareed, because I have no idea what he is thinking about for a general election campaign," Clinton said. "As I've said many times, I do not think he's our strongest nominee against Donald Trump."

Clinton and Sanders fought a bitter race for the Democratic presidential nomination four years ago, and the rift between both candidates - and their supporters - was front and center in the final months of the campaign.

Sanders waited more than a month to endorse Clinton after losing the nomination to her, and even then, his reluctance to fully embrace her candidacy was evident on the campaign trail that fall.

By contrast, Clinton and Biden worked together in the Obama administration; the then-vice president endorsed Clinton for president in June 2016, more than a month before Sanders did, although Biden also had praise for some of Sanders' policy positions.

In the CNN interview that aired Sunday, Clinton nodded to the 2016 tensions between her campaign and Sanders' and said she hopes the same dynamic doesn't play out between the Sanders and Biden camps this time around should Biden win the nomination.

Sanders' "failure and the behavior of a lot of his top aides, and certainly many of his supporters - up to the convention, at the convention, and even up to Election Day - was not helpful," Clinton said. "I had thought we would unify. That's what we'd always done before, and that's what I expected. I certainly tried to do that when I ran against Barack Obama and worked very hard for him."

Sanders said Sunday that he and Biden are united in their goal of defeating Trump in November.

"What Joe has said is, if I win the nomination, he'll be there for me," Sanders said on "Fox News Sunday." "What I have said if he wins, I'll be there for him. ... So, Biden and I, no matter who wins this thing, we'll be together in defeating Trump."

Clinton also said on CNN that Biden showed with his strong Super Tuesday performance that he is "building the kind of coalition that I had, basically," although she stopped short of endorsing him.

"You looked at those numbers - people are turning out, and they're turning out to try to pick the person they think would be the best president, but also the person as our nominee who would most likely be able to beat Trump," she said. "And clearly, the Trump campaign and Trump himself know who they don't want to run against and know who they do want to run against."

Asked whether she believes the eventual Democratic nominee should choose a woman as his running mate, Clinton said that decision is up to the nominee. She noted that she would personally "love to have a woman on the ticket, finally, again," but that the ability of a potential vice presidential candidate to help the Democratic ticket win the electoral college also should be a consideration.

"We've had two women vice presidential candidates - one for the Democrats, one for the Republicans," Clinton said. "But, obviously, I'd like to keep that moving and actually have it happen in this election, that someone would be the first woman vice president. But whoever the nominee is has to take a really hard look at the electoral college - what will help him, because that's who it's down to."