By a bipartisan vote of 363 to 40, the Democratic-controlled House passed a multibillion-dollar effort that would expand safety-net programmes to help those who could be thrown out of work in the weeks to come.
The White House physician later indicated that Trump's interactions were low-risk and that testing was not necessary.
Trump's speech cheered Wall Street and sent the Dow up 9.3 per cent, much needed good news after a week that saw the index suffer its worst day of trading since 1987 and the Federal Reserve inject $1.5 trillion into money markets to keep the financial system running. His action will open up $50 billion for local and state governments to respond to the outbreak.
He said: "I'm urging every state to set up emergency operations centres effective immediately".
He said he was glad that Brazilian President Jair Bolsonaro had tested negative for the virus, after the pair sat next to each other for an extended period of time last weekend at Mr Trump's Mar-a-Lago club.
Health Secretary Alex Azar and the Food and Drug Administration (FDA) will be empowered to waive rules for developing medications and tests and for promoting telemedicine.
Karnataka man, who died of coronavirus, had hypertension and asthma
Karnataka Health Minister B Sriramulu also tweeted confirming about one more COVID-19 positive case in the state. In Afghanistan, the number of confirmed cases rose to seven from four, the health ministry said on Wednesday.
Globally there are over 137,000 cases and over 5,000 deaths.
As the House prepared to vote late on Friday, US House of Representatives Speaker Nancy Pelosi touted the hard-fought package that would provide free testing, sick pay for workers, enhanced unemployment benefits and bolstered food programs.
In keeping with the Republican philosophy of involving the private sector, Trump announced several initiatives with corporations while declaring the emergency. "Right now we are hearing that some of the fights and some of the gridlock is because people are trying to put pro-life provisions into this", she told Fox News' Brett Baier.
"I'm working with the Administration as we address coronavirus". Anyone employed by a company larger than that - which is more than half of all American workers - is ineligible.
Trump said that under the emergency, the rules would be made flexible to allow doctors and hospitals to effectively deal with the crisis.
Requires employers with less than 500 employees to provide two weeks of paid sick leave for people who become infected with the coronavirus or have to care for someone who is, as well as people who are quarantined or whose place of work or children's school is closed due to coronavirus.
The experience of sick people that the Times interviewed underscores how hard it can be for people in the United States to find out if they have the coronavirus, despite Trump's announcement last week that anyone who wants a test can receive it.