Barack Obama officially endorsed his former Vice President Joe Biden on Tuesday in a nearly 12-minute long video.

“If there’s one thing we’ve learned as a country from moments of great crisis, it’s that the spirit of looking out for one another can’t be restricted to our homes, or our workplaces, or our neighborhoods, or our houses of worship,” the former president said. “It also has to be reflected in our national government.”

He continued, “The kind of leadership that’s guided by knowledge and experience, honesty and humility, empathy and grace — that kind of leadership doesn’t just belong in our state capitols and mayors offices. It belongs in the White House.”

“And that’s why I’m so proud to endorse Joe Biden for President of the United States,” he added.

Obama’s video comes one day after Sen. Bernie Sanders (I-Vermont) endorsed Biden. Sanders had been Biden’s top competitor for the Democratic nomination but suspended his campaign as he lost momentum and voters rallied around Biden.

Obama appealed directly to Sanders supporters, many of whom feel disenfranchised by Biden’s moderate platform and less progressive agenda.

“To meet the moment, the Democratic Party will have to be bold,” Obama said. “I could not be prouder of the incredible progress that we made together during my presidency. But if I were running today, I wouldn’t run the same race or have the same platform as I did in 2008. The world is different. There’s too much unfinished business for us to just look backwards. We have to look to the future.”

He continued, “Of course Democrats may not always agree on every detail of the best way to bring about each and every one of these changes, but we do agree that they’re needed. And that only happens if we win this election.”

Obama’s comments echo what Sanders said during his formal endorsement — Democrats should be unified in voting President Donald Trump out of office.

Biden thanked Obama for his backing in a tweet on Tuesday.

“This endorsement means the world to Jill and me,” he wrote. “We’re going to build on the progress we made together, and there’s no one I’d rather have standing by my side.”