Donald Trump said he "thinks" his experimental coronavirus treatment is "going well" after he was dramatically airlifted to hospital amid reports he is "struggling to breathe".

In extraordinary scenes at the White House on Friday, Trump, 74, was rushed via helicopter to Walter Reed medical center near Washington DC out of an "abundance of caution" after he was struck down with coronavirus symptoms - putting the US election in jeopardy with just weeks to go.

    Going welI, I think! Thank you to all. LOVE!!!
    — Donald J. Trump (@realDonaldTrump) October 3, 2020

Hours after he was transported to the hospital via presidential helicopter Marine One, Trump tweeted: "Going well, I think! Thank you to all. LOVE!!!"

After it was reported Trump was "struggling to breathe," White House doctor Sean P Conley said Trump was given a dose of Remdesivir.

Remdesivir - used for the treatment of Ebola, SARS, and hepatitis C - is an antiviral medication that is designed to interfere with the virus’s ability to copy its genetic material.  

In exactly one month, Mr Trump faces Joe Biden in the presidential election.

Trump positive covid test latest:

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Conley said in an update late on Friday that Trump was "doing very well" and "is not requiring any supplemental oxygen".

The President revealed early on Friday morning that him and First Lady Melania Trump had tested positive for Covid.

The doctor said Trump was given a dose of Remdesivir and is "resting comfortably."

The drug was approved for emergency use in May amid the outbreak.

Earlier on Friday CNN reported after Trump's hospitalisation that White House officials "have serious concerns about Trump's condition tonight."

Sources said Trump's "symptoms are worse than those of the First Lady at this point."

One adviser to Trump told CNN: "This is serious."

Trump is reported to be "very tired, very fatigued, and having some trouble breathing."

A White House official insisted Trump is “fatigued," but he's not "deteriorating."

The official told CNN the public shouldn't be worried, and that Trump is taking this "very seriously."

However, contrary to CNN's sources, a senior Trump administration official told Fox News that Trump is not struggling to breathe.

The official said such reports about Trump having a hard time are "downright disgraceful."

House Minority Leader Kevin McCarthy, a Republican, said per Fox News that he's spoken with Trump, and described him as "upbeat."

McCarthy said Trump "told me that he appreciates all the prayers and support from everyone. Our president is strong and will beat the virus!"

Earlier on Friday, Trump was seen for the first time since he confirmed he had the deadly virus, giving a "thumbs up" as he walked across the White House South Lawn to Marine One.

Shortly after he was transported to the military hospital in Bethesda, Maryland, Trump tweeted out a video of himself thanking "everybody for the tremendous support."

"I'm going to Walter Reed hospital. I think I'm doing very well. But we're going to make sure things work out," Trump said.

He said First Lady Melania Trump, 50 – who also tested positive for COVID – "is doing very well."

"So thank you very much. I appreciate it, I will never forget it," the president said. "Thank you."