President Joe Biden is scheduled to return to the White House Tuesday for the first time since announcing he is stepping aside from the 2024 presidential race.

The return also comes after the president began isolating in Rehoboth, Delaware, after testing positive for COVID-19 last week.

Biden will depart Delaware Tuesday afternoon and is estimated to be back at the White House by 2:30 PM ET.

No other events are currently on the president's schedule.

Sen. Bernie Sanders, I-Vt., said Monday night that he wants to see Vice President Kamala Harris campaign for president "on issues of importance for the working class of this country."

In an interview with Linsey Davis on ABC News Live, Sanders said he wants Harris to "stand up to corporate greed and massive income and wealth inequality."

He also called for her to support raising the minimum wage and expand Social Security and Medicare. Sanders also said he wants Harris to "demand that the wealthy start paying their fair share of taxes."

If Harris takes on those issues, Sanders said he believes she "can win big," but he still wants to “have just another conversation” with the vice president.

Sanders had been supporting President Joe Biden in the 2024 election before Biden's withdrawal from the campaign on Sunday night.

"This has been a very unprecedented situation. I am not overjoyed about the way that President Biden was treated," Sanders said. "We are where we are right now, and I'm 99% sure that the vice president will be the nominee. And then she has an excellent chance to win this election."

While he still has plans to speak with Harris, he is committed to keeping former President Donald Trump from returning to the White House.

"Well, I'm going to do everything I can to see that Donald Trump, [the] most dangerous president in American history, is defeated," Sanders said.

-ABC News' Maria Olloqui and Jolie Lash

The American Federation of Labor and Congress of Industrial Organizations has thrown its unanimous support behind Kamala Harris in the 2024 presidential race.

"From day one, Vice President Kamala Harris has been a true partner in leading the most pro-labor administration in history," AFL-CIO President Liz Shuler wrote in a statement Monday.

"At every step in her distinguished career in public office, she’s proven herself a principled and tenacious fighter for working people and a visionary leader we can count on," Shuler continued.

"From taking on Wall Street and corporate greed to leading efforts to expand affordable child care and support vulnerable workers, she’s shown time and again that she's on our side. With Kamala Harris in the White House, together we'll continue to build on the powerful legacy of the Biden-Harris administration to create good union jobs, grow the labor movement and make our economy work for all of us," she added.

The support for Harris' campaign comes as some of the nation's largest unions also have offered support, praise and outright endorsements to the vice president.

The Service Employees International Union, whose 2 million members make it the nation's largest private sector union, endorsed Harris on Sunday. So did Local 3000 of the United Food and Commercial Workers, a labor organization in the Pacific Northwest, which drew attention last week when it became the only Biden-aligned union to call for him to step aside.

-ABC News' Beatrice Peterson and Max Zahn

Vice President Kamala Harris thanked President Joe Biden for endorsing her in the 2024 presidential race on Monday.

"It is my great honor to have Joe's endorsement in this race," Harris said while speaking to campaign staff in Delaware.

Echoing Biden's comments on his commitment to the Democratic campaign, Harris said, "Joe is not done, far from it."

"He knows there is still more work to do and our nation will continue to praise his bold and visionary leadership as president," Harris said, adding, "Thank you, Joe."

-ABC News' Gabriella Abdul-Hakim, Fritz Farrow and Will McDuffie