Does Bernie Sanders' Tuesday campaign appearance with presumptive Democratic nominee Hillary Clinton, where it is widely expected he will finally offer his endorsement, signal the end of his presidential campaign?

"No," Sanders spokesman Michael Briggs told the Washington Examiner. "He's going to Philadelphia and still taking delegates to the convention. They have a lot to be proud of."

The two Democratic candidates' first joint appearance comes over one month after Clinton officially secured the necessary number of delegates to become the Democratic nominee. But, since her nomination will not be final until the convention, Sanders has stayed in the race as a means of promoting his progressive agenda and shifting the party platform to the left.

In the past week, Clinton adopted progressive elements of Sanders' healthcare and education plans. Sanders supporters have also scored key victories writing the platform.

At the event in Portsmouth, N.H., the two will "discuss their commitment to building an America that is stronger together and an economy that works for everyone, not just those at the top," according to the Sanders campaign. But, Sanders officials say he won't push for more concessions from Clinton.

"I think that those are two very significant accomplishments," Briggs said of Clinton's policy shifts on education and healthcare. "We had a good thing over the weekend in Orlando, adopting the most progressive platform in history. The two campaigns are coming together more and more."

This coming together has been a delicate process for Sanders, who has tried to reconcile accepting Clinton's eventual nomination with continuing his campaign until the delegates vote in Philadelphia.

"I think we've made a lot of progress and we're just going to leave it here for now," Briggs said.

Although Sanders will help Clinton in New Hampshire, a state where he beat her by over 20 points during the primary, the Vermont senator is not yet committed to more campaign stops for Clinton. When asked if Sanders would appear regularly on the trail or speak at the convention, Briggs laughed and said, "Well, stay tuned."