Biden breaks his silence 24 hours after extraordinary decision to drop out by calling into his old campaign office during Kamala Harris' visit

President Joe Biden broke his silence over 24 hours after his extraordinary decision to drop out of the 2024 race with a phone call to what has now become Kamala Harris' campaign headquarters.

The 81-year-old spoke in a scratchy voice to campaign staffers from COVID isolation at his Rehoboth Beach, Delaware, home and told Harris: 'I'm watching you kid'.

He pledged to still be involved in the reelection fight and said he would continue to hit the campaign trail as he interacted on loudspeaker with his staffers who now work for Harris.

Biden's comments followed questions of why he hadn't been seen or heard from since he made the bombshell announcement on X Sunday afternoon that he was stepping aside.

'I know yesterday's news is surprising and hard for you to hear, but it was the right thing to do,' the president said. 

'I know it's hard because you poured your heart and soul into me, to help us win this thing, help me get this nomination, help me win the nomination and then go on to win the presidency,' he continued. 

Already there were signs that the campaign had moved on, with signage that read 'Harris for President,' 'Kamala,' and 'Restore Roe' hung on the walls of the office.

Vice President Kamala Harris (left) and second gentleman Doug Emhoff (right) hold hands before a crowd of campaign staffers, after President Joe Biden called in during Harris' visit Monday and say that his decision to bow out of the race was for the best 

Vice President Kamala Harris visits what had been the headquarters for the Biden-Harris campaign in Wilmington, Delaware on Monday 

There was one wall in the Delaware office that remained covered in signs with the 'Biden-Harris' logo.

As Harris took the podium, she noted how Biden was still on the call. 

'We love Joe and Jill,' the vice president said. 

'It's mutual,' Biden interjected from the phone line.

'I knew you were still there, you're not going anywhere Joe,' she said laughing. 'I love you Joe,' she added. 

Harris thanked the campaign staff and announced that current campaign chair, Jen O'Malley Dillon, would run her campaign. The current Biden-Harris campaign manager, Julie Chavez Rodriguez - a former Harris Senate staffer - would also stay on. 

'And I know it's been a roller coaster and we're all filled with so many mixed emotions about this,' Harris said. 'I just have to say, I love Joe Biden, I love Joe Biden and I know we all do and we have so many darn good reasons for loving Joe Biden.' 

'And I have full faith that this team, is the team, will be the reason we win in November, you all who are here,' the soon-to-be Democratic nominee continued. 

Vice President Kamala Harris speaks at what had been the Biden-Harris campaign headquarters in Wilmington, Delaware on Monday, as she took over the campaign operation as the likely soon-to-be Democratic nominee 

Vice President Kamala Harris (right) and second gentleman Doug Emhoff (left) arrive in Wilmington, Delaware Monday afternoon to appear before the Biden-Harris campaign staff as the VP takes over the campaign operation 

President Joe Biden was last seen publicly on Wednesday after contracting COVID-19 and departing Las Vegas for his Rehoboth Beach, Delaware home. It was there that he made the decision to drop out of the 2024 presidential race and hand the operation over to Harris 

Harris said she was honored to have the president's endorsement. 

 'It is my intention to go out and earn this nomination and to win,' she said. 

So far no other mainstream Democrat appears to be challenging Harris, though self-help guru Marianne Williamson, who ran against Biden in the 2024 primaries, pushed that there should be an open convention when the Democrats meet in Chicago in August.

Democratic lawmakers, donors and grassroots supporters have coalesced around Harris, who would be the first woman and woman of color to be elected U.S. president. 

A spokesperson for the campaign said that the Harris campaign raised $81 million in donations since Biden bowed out and more than 28,000 individuals signed up to volunteer. 

Biden's campaign staff had been blindsided with the news that he was dropping out of the 2024 race - finding out via the X post Sunday like the rest of the American people. 

'No one had a heads up before the tweet posted,' a campaign source told DailyMail.com Sunday. 'Which to me is an insane way to treat the 1,300 people that work for you,' the source added. 

'Kamala' signs are seen on display around what had been President Joe Biden's reelection headquarters in Wilmington, Delaware. On Monday, Biden called in while Harris was visiting campaign HQ, as she takes over the campign 

Vice President Kamala Harris (left) kisses her husband, second gentleman Doug Emhoff (right), before delivering remarks Monday at the Wilmington, Delaware campaign headquarters she was inheriting from President Joe Biden 

At 5 p.m. Sunday on an all-staff call, O'Malley Dillon assured aides that their jobs would remain. 

She also acknowledged that it was 'hard for staff who may have gotten the news while they were working or door knocking,' but that it was 'important' that they heard from the president 'in his own words.' 

Shortly after Biden posted the letter saying he was bowing out of the race he said in a follow-up post on X that he was endorsing Harris to take his place as the Democratic nominee. 

'I'm hoping you'll give every bit of your heart and soul that you gave to me to Kamala,' Biden said on loudspeaker Monday. 'And I want you to know, I won't be on the ticket but I'm still going to be fully, fully engaged.'

'I've got six months left of my presidency, I'm determined to get as much done as I possibly can - both foreign policy and domestic policy,' he continued, making mention of 'working for an end to the war in Gaza.'

The president added that he would be doing 'whatever Kamala wants me or needs me to do in addition.'

'So let me be real clear. We're still fighting in this fight together. I'm not going anywhere,' the president said.

He hasn't been seen publicly since Wednesday since testing positive for COVID-19.

It remains unclear when the president plans to return to Washington.