US President Donald Trump has returned to work and held briefings at the Oval Office less than a week after he tested positive for coronavirus.

The president has had no Covid-19 symptoms for more than 24 hours and has been fever-free for more than four days, his doctor, Sean Conley, said.

In a video message on Wednesday, Mr Trump said he felt "great", adding: "I think this was a blessing from God."

He said he wanted all Americans to have access to the treatments he was given.

Mr Trump also promised to provide the drugs produced by Regeneron Pharmaceuticals free of charge.

He said the experimental antibody cocktail he was given last week was a cure rather than a therapeutic measure, adding that hundreds of thousands of doses were nearly ready. But Regeneron's drugs have not been approved by federal regulators.

"This was a blessing in disguise - I caught it, I heard about this drug, I said let me take it and it was incredible," he said, adding that he would seek emergency use authorisations for the drugs.

President Trump renewed his attacks on China, telling Americans: "You're not going to pay for it. It wasn't your fault that this happened. It was China's fault. And China is going to pay a big price,,, This was China's fault."

Earlier, Dr Conley said the president had not needed any supplemental oxygen since going to hospital on Friday. He was discharged on Monday.

Mr Trump's supporters say that he has shown leadership since his release from hospital. But his opponents say his behaviour has become increasingly erratic.

The White House has also set out new safety measures after President Trump's return from hospital and the news that another aide had Covid-19.

The presidential election is on 3 November. One key issue in the run-up to polling day is a coronavirus stimulus package for the economy. Mr Trump appeared to abandon negotiations with the Democrats on Tuesday, only to say later he would agree to some measures individually.