UPDATE 7/12/16: Bernie Sanders officially endorsed Hillary Clinton for president at a campaign event in New Hampshire on Tuesday morning.

NBC News reports that Sanders extended emphatic support to Clinton saying:

I have come here to make it as clear as possible as to why I am endorsing Hillary Clinton.

This campaign is not really about Hillary Clinton or Donald Trump or Bernie Sanders. This campaign is about the needs of the American people and addressing the very serious crises that we face. And there is no doubt in my mind that as we head into November, Hillary Clinton is far and away the best candidate to do that.

Original story below.

Bernie Sanders is expected to endorse former rival Hillary Clinton on Tuesday, effectively making her the presumptive Democratic nominee. Sanders' appearance at a Clinton rally in New Hampshire was announced early Monday, and TIME reports the appearance will also serve as the Vermont senator's formal endorsement.

A statement from the Clinton campaign promises the two will "discuss their commitment to building an America that is stronger together" at Portsmouth High School, a union that both campaigns have slowly embraced in recent weeks. In June, Sanders stopped short of offering a full co-sign to the Clinton campaign but said he will offer her his vote in November. "I think the issue right here is, I'm going to do everything I can to defeat Donald Trump," Sanders said at the time, speaking during an appearance on Morning Joe.

Given that the Democratic National Convention in Philadelphia is now just two weeks away, Sanders' move toward unifying Democrats isn't exactly unexpected. Sanders' endorsement of Clinton, however, could prove a controversial move among his most fervent supporters.

Though the extent of such movements are hard to measure, some frustrated Sanders supporters have repeatedly refuted any possibility of following the Vermont senator's lead when it comes to standing with Clinton in an effort to prevent a Trump presidency.

Last November, Sanders firmly asserted his policies as a stark contrast to those of Clinton. "I disagree with Hillary Clinton on virtually everything," Sanders told the Boston Globe at the time. "What is important to look at is the record, the track record that Hillary Clinton has had for her long and distinguished career as a public figure."

Was Sanders able to successfully add some of his own unique policies to Clinton's presidential platform? Tuesday should bring answers.