Today, President Biden is scheduled to return to the White House after isolating in Delaware with COVID. Yesterday, America hearing from him for the first time since dropping out of the race over the phone.

To be real clear, we're still fighting in this fight together. I'm not going anywhere. I want you to know you've always had my back, and I promise you, I will always have your back, and I'm anxious for you all to hear from come on.

Well, he says he's not going anywhere, but as reports say, he's canceled nine upcoming trips. The question remains, is Biden fit to serve until January? Here to react is Fox News Medical contributor Dr. Marc Siegel. Dr. Siegel, thanks for joining us. Knowing what you know about medicine, is he fit to serve for the next six and a half months?

Well, let me put it to you this way, Angely. I'm concerned about him. I have compassion for him. I think it's been clear to all of us. Now, the American public, before it was neurologists and physicians like me, but now it's clear to everyone, and he's struggling, and I feel compassion for him But I feel more compassion for us because the key word today is cover up. What did people know and when did they know it? Kamala Harris was saying he was fit. Everyone's saying he's fit. He's still not saying he's not fit, but he's the last to know. What is the White House doing? Where's the physician? Where is Biden's doctor? Where's Kevin O'Kharnoush coming forward and saying, Look, he's got COVID. Okay, how's he doing mentally? How's he doing cognitively? None of that has come forward. By the way, another disservice here is to call this about age. It's not about age. Plenty of elderly people do quite well, but the President is struggling, and that's the concern. Looking back, we're going to see this as a cover up being worse than the crime again, like in the 1970s. We need full transparency coming out of the White House.

Yeah, Donald Trump agrees with you. He says there needs to be an investigation. Listen to this.

You had people to the American public, and I tell you what, you ought to take a look at his doctors because his doctors I've given him this wonderful report. I'm not a doctor, but I saw him the other day was unable to get up the children stairs going into Air Force One.

Yeah, his medical team was not honest with us, Dr. Siegel. Should there be accountability? This is the number one job, the top job in our country, and the President is the one who protects us. To know our President has to drop out of the race and is not able to run again because of cognitive decline, is he able to still run the country? I know you've answered that, but answer this question. What about the doctors? Will they be held accountable?

They need to answer that question, by the way. I'm not running from that. Listen, Ainsley, ask his doctors whether he's capable of running the country right now. Ask Kamala, ask the people that are behind the scenes. Can we trust them? I don't trust them because they're hiding, because they're obfuscating, because there's no transparency. But look, if the doctor says, I'm not allowed to talk because of patient privacy, well, who's telling him not to talk? Who's keeping him from coming forward? I want to hear from the President's physician whether he is fit to serve right now. Look, there's two wards going on. This is a hugely important issue. We got four months left before the election, even. I think it's incredibly important. But let's not focus so much on Biden. Let's focus on compassion for Biden, but compassion for us, the country, because we're not being told anything.

Dr. Siegel, thank you so much for coming on with us.

I'm Steve Ducey. I'm Brian Kilme.

I'm Ainsley Earhart. Click here to subscribe to the Fox News YouTube page to catch our hottest interviews and most compelling analysis.