He was joined by Vice-President Mike Pence and Deborah Birx, the White House coronavirus taskforce co-ordinator, the BBC reported.

"We have a lot of great, brilliant minds working on this," he said.

"Unfortunately we're not very close to testing because when testing starts it takes a period of time, but we'll get it done."

Dr Anthony Fauci, the US government's top infectious diseases expert, had previously said that a vaccine will likely take 12-18 months to be approved for widespread use. Most health experts also agree that it would take at least 12-18 months before a vaccine is ready.

After Trump, Vice-President Mike Pence said the data continues to show "promising signs of progress" in the US fight against coronavirus.

Major virus hotspots including the New York Metro Area, New Jersey, Connecticut, Detroit and New Orleans "all appear to be past their peak", Pence said.

"Our only conclusion is that we're getting there, America," he added.

"If we continue these mitigation efforts in the days ahead... we do believe by early summer we could be in a much better place as a nation, with much of this coronavirus epidemic behind us."

He says 16 states have released formal reopening plans so far.

Vice-President said that 4.93 million coronavirus tests have been completed across the US, adding that commercial labs surpassed 100,000 tests yesterday.

Pence says that he is "encouraged" by states' "phased approach" to reopening their economies.

"We're slowing the spread, we're protecting the most vulnerable, we're saving lives and every single day we are one day closer to opening up America again," Pence said.