Donald trump said on monday afternoon that he would shortly be leaving walter reed military hospital, where he has spent the last three nights being treated for coronavirus.

I will be leaving the great walter reed medical center today at 6:30 p.m. feeling really good! mr trump wrote on twitter. dont be afraid of covid. dont let it dominate your life. we have developed, under the trump administration, some really great drugs & knowledge. i feel better than i did 20 years ago!

Mr trumps tweet came shortly before his doctors were expected to update the nation on his condition and after the white house said it was optimistic that the president would be discharged.

We are still optimistic that he will be able to return to the white house later today, mark meadows, the white house chief of staff, told fox news earlier on monday. he continued to improve overnight and is ready to get back to a normal working schedule.

Mr meadows said the medical team treating mr trump at the military medical centre in suburban maryland would make a determination later on monday about whether to discharge the president.

Despite the optimism, the outbreak that has struck mr trumps inner circle continued to spread, with kayleigh mcenany, the white house press secretary, announcing she had tested positive for the virus.

In a statement, ms mcenany said she had received the positive result on monday but was experiencing no symptoms. she added that she would begin to quarantine immediately.

The president sparked intense criticism on sunday evening after he briefly left walter reed in an suv to thank supporters who were gathered outside the facility. critics accused him of conducting a political stunt that put his driver and secret service team at risk of contracting the virus.

On monday, mr trump hit back at his critics in a tweet: it is reported that the media is upset because i got into a secure vehicle to say thank you to the many fans and supporters who were standing outside of the hospital for many hours, and even days, to pay their respect to their president.

He added: if i didnt do it, media would say rude!!!

Over the past three days, mr trumps oxygen reading has dropped to levels that concerned doctors on two occasions. the president has also taken an experimental drug cocktail and remains in the middle of a five-day course of remdesivir, which has not been fully approved by regulators.

If you look at the therapeutics which im taking right now, some of them and others that are coming out soon that are looking like, frankly, theyre miracles, mr trump said in a video posted to his twitter account at the weekend.

On sunday, his doctors revealed that he was also being given an anti-inflammatory steroid called dexamethasone. the world healthorganization recommends the drug for patients with severe covid-19, while the us national institutes of health recommends it for patients who require artificial ventilation or supplemental oxygen.

Ms mcenanys positive test widens the number of trump aides who have been diagnosed with the virus. bill stepien, the presidents campaign manager, tested positive last week. kellyanne conway, a former top white house aide, and chris christie, the former new jersey governor, both caught the virus last week after helping mr trump with his debate preparation.

A justice department spokesperson on sunday evening said bill barr, the attorney-general, had tested negative but was quarantining. mr barr was at a white house rose garden in late september that was also attended by several people who were later diagnosed with covid-19, including two senators and ms conway.

Judd deere, the deputy white house press secretary, said he was also quarantining as a precautionary measure. mr deere said he had been with mr trump on thursday, the day the president was diagnosed with the virus. mr deere has not tested positive.

Mr trump was hospitalised on friday evening after testing positive on thursday. during his three days at the medical facility, the white house and his main doctor sean conley have given conflicting accounts of his condition and on occasions made statements that appeared designed to play down concerns about his health.

Robert obrien, the us national security adviser, on sunday said mr trump wanted to return to the white house but would stay at the hospital because he was approaching a critical phase of his illness.

Day seven and eight are the critical days, so i think the doctors want to make sure theyre there for the president. but hours later mr conley and the doctors at walter reed suggested that mr trump could be discharged as early as monday.