After waging a long campaign against Hillary Clinton and 'revolution' against a political system he described as rigged, Vermont Senator Bernie Sanders said he'll cast his ballot for Clinton in November.

'Yes,' Sanders responded when asked on MSNBC whether he would vote for Clinton.

But he stopped short of an endorsement, and immediately started speaking about the threat of Donald Trump when asked about it.

'I think the issue right here is I'm going to do everything I can to defeat Donald trump. I think Trump in so many ways would be a disaster of this country if he were elected president,' Sanders said.

'I'm pretty good at arithmetic, and what I know is that Hillary Clinton has more than I do, and she has a lot more superdelegates than I do,' he said on MSNBC.

But asked just minutes later on CNN who he'll vote for, Sanders responded: ''In all likelihood, it will be Hillary Clinton.'

Sanders answered 'yes' when asked on MSNBC whether he'd vote for Hillary Clinton

But he added a 'probably' when asked who he'd vote for on CNN

He continued: 'But what I also know is we're bringing 1,900 delegates into the convention, that we have received 13 million votes, and that what I am going to be doing right now – we are gonna be urging millions of people to get involved in the political process.'

Sanders, who has been negotiating with Clinton since she beat expectations and trounced him in the California primary this month, said he wants to make sure the party represents 'working people.'

'What I'm trying to do right now is to make sure that the Democratic Party becomes a party that represents working people, not Wall Street, that is prepared to have an agenda that speaks to the need of creating millions of jobs, raising the minimum wage to 15 bucks an hour, dealing with climate change, dealing with pay equity,'he said.

Democrats have been anxious for Sanders to get on board, and occasionally furious at his pace, in order to unify the party and begin winning over any disappointed holdouts from the Sanders camp, including younger voters who backed him in droves.

Democrats are certain they'll be stronger if Sanders gets fully behind the presumed nominee and brings his devoted followers along with him

Sanders' incredible 'revolution' was fueled in part by his attacks on entrenched interests and on Hillary Clinton herself

Sanders spoke to his supporters in Manhattan Thursday

Although Clinton has been leading Donald Trump in the polls, tight races in Ohio and Pennsylvania are cause for party concern.

Clinton campaign press secretary Brian Fallon brushed off the lack of a more full-throated endorsement when asked about it by Andrea Mitchell on MSNBC.

'I think he had his pompoms there Andrea they were just off camera so you couldn't see them in the shot,' he quipped.

'I’m going to leave it to him in terms of how he wants to characterize his support for Hillary Clinton,' Fallon added.

But Sanders brushed off talk of disunity. 'You talk about disunity, I talk about involving the American people in the political process and wanting to have a government and a party that represents all of us,' he said.

In the CNN appearance, Sanders was able to look on the bright side after going further than almost anyone in politics predicted but still failing to topple the Clinton juggernaut.

He said if he could get the party to back free public college tuition, a hike in the minimum wage to $15 minimum and a strong climate change plank, "you know what? I think I've run a winning campaign."