Dr Anthony S. Fauci, the nation’s top infectious disease expert, told House lawmakers that the nation is experiencing a “disturbing surge” of coronavirus infections as states reopen too quickly and without adequate plans for testing and tracing the contacts of those infected with the virus.

In a break with President Trump’s upbeat assessments of the pandemic’s trajectory in the US, Dr Fauci told the House Energy and Commerce Committee that while some states like New York, were “doing very well” in controlling spread of the virus, the surge in other states was “very troublesome to me”.

“The next couple of weeks are going to be critical in our ability to address those surges we are seeing in Florida, Texas, Arizona, and other states,” Dr Fauci told the panel as he and other leaders of the White House coronavirus task force appeared together for the first time in more than a month to brief Congress.

In their testimony, the officials said they had made progress in confronting the virus, including towards a vaccine that Dr Fauci said he was “cautiously optimistic” would be available by early next year and expanding the availability of testing in doctor’s offices by late autumn. But they also made clear they did not agree with Trump, who last week claimed in an interview with Fox News that the virus would simply “fade away”.

In his opening statement, Dr Robert R. Redfield, the director of the Centers for Disease Control and Prevention, called the pandemic “the greatest public health crisis our nation and world have confronted in a century”, and warned that the outbreak would coincide with flu season later this year, straining hospitals and health workers.

The doctors were also grilled on Trump’s claim at a campaign rally in Tulsa that he had asked “my people” to “slow the testing down” because increased screening was revealing more infections, making the country look bad.