Former President Barack Obama endorsed Joe Biden in a video released Tuesday, saying his former vice president “has the character and the experience to guide us through one of our darkest times and heal us through a long recovery.“

The endorsement came one day after Sen. Bernie Sanders, I-Vt., offered Biden his endorsement during a livestream. Sanders ended his campaign for president last week, leaving Biden as the apparent nominee.

"Choosing Joe to be my Vice President was one of the best decisions I ever made, and he became a close friend," Obama said. "And I believe Joe has all the qualities we need in a president right now. He’s someone whose own life has taught him how to persevere; how to bounce back when you’ve been knocked down."

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"Through all his trials, he’s never once forgotten the values or the moral fiber that his parents passed on to him, and that made him who he is," Obama added. "That’s what steels his faith — in God, in America, and in all of us."

Obama pointed to Biden's role assisting in the recovery from recession in the late 2000s, his efforts in combating past outbreaks during their administration, and his work in furthering Obama's foreign policy agenda.

The former president added that he knows Biden will "surround himself with good people — experts, scientists, military officials who actually know how to run the government and care about doing a good job running the government, and know how to work with our allies, and who will always put the American people’s interests above their own."

I’m proud to endorse my friend @JoeBiden for President of the United States. Let's go: https://t.co/maHVGRozkX — Barack Obama (@BarackObama) April 14, 2020

Biden responded to the endorsement on Twitter, writing, "Barack — This endorsement means the world to Jill and me. We’re going to build on the progress we made together, and there’s no one I’d rather have standing by my side."

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Obama had publicly remained on the sidelines as the primary played out, although he offered advice to candidates behind the scenes. In recent weeks, he had several calls with Sanders, as part of discussions that also included Biden about how best to unite the party, sources familiar with the discussions told NBC News last week.

By remaining out of the public spotlight, Obama hoped to help unify the party once the primary contest had wrapped.

"Now Joe will be a better candidate for having run the gauntlet of primaries and caucuses alongside one of the most impressive Democratic fields ever," Obama said. "Each of our candidates were talented and decent, with a track record of accomplishment, smart ideas, and serious visions for the future. And that’s certainly true of the candidate who made it farther than any other — Bernie Sanders."

"Bernie’s an American original — a man who has devoted his life to giving voice to working people’s hopes, dreams, and frustrations," he continued. "He and I haven’t always agreed on everything, but we’ve always shared a conviction that we have to make America a fairer, more just, more equitable society. We both know that nothing is more powerful than millions of voices calling for change. And the ideas he’s championed; the energy and enthusiasm he inspired, especially in young people, will be critical in moving America in a direction of progress and hope."

In recent weeks, Obama has ramped up his presence on social media, posting mostly about information on the COVID-19 outbreak that he believes should be widely shared.

Last week, President Donald Trump questioned why Obama had yet to endorse Biden.

"I'm sure he's got to come out at some point because he certainly doesn't want to see me for four more years," Trump said, adding: "When is it going to happen? When is it going to happen? Why isn’t he?"

Trump campaign manager Brad Parscale said that Obama had "no choice" but to support Biden because he's the lone remaining Democratic candidate standing and that Trump "will destroy" Biden this fall.

When Biden announced his candidacy, he was soon asked why Obama hadn't already endorsed him.

"I asked President Obama not to endorse,” he told reporters. “Whoever wins this nomination should win the nomination on their own merits."

Obama's involvement at the end of the race mirrors 2016. Once former Secretary of State Hillary Clinton clinched the nomination in June, Obama met with Sanders at the White House before making his endorsement of Clinton public. Sanders then waited another month before endorsing Clinton himself. This time, however, Sanders announced his endorsement of Biden prior to Obama's rollout.

While Obama remained on the sidelines, Biden has all but bear-hugged the former president in his comments on the campaign trail, as Obama remains highly popular with Democrats.

"If you notice, every major historian has written about the presidency and the vice presidency, and they've said of late, that no vice president or president has ever been closer than Barack Obama and Joe Biden in American history," he told voters in Iowa in January. "That's been the consensus. And there's a reason for that, because we both trusted each other, completely. And we knew, and he knew from the beginning, I would never, ever, ever do anything, that was inconsistent with his interest."

In his endorsement, Obama said "one thing everybody has learned by now is that the Republicans occupying the White House and running the U.S. Senate are not interested in progress."

"They’re interested in power," he continued, adding, "Repeatedly, they’ve disregarded American principles of rule of law, and voting rights, and transparency — basic norms that previous administrations observed regardless of party. Principles that are the bedrock of our democracy."

"So our country’s future hangs on this election. And it won’t be easy," he continued. "The other side has a massive war chest. The other side has a propaganda network with little regard for the truth. On the other hand, pandemics have a way of cutting through a lot of noise and spin to remind us of what is real, and what is important. This crisis has reminded us that government matters. It’s reminded us that good government matters. That facts and science matter. That the rule of law matters. That having leaders who are informed, and honest, and seek to bring people together rather than drive them apart — those kind of leaders matter."