Nearly one in three Americans was under orders on Sunday (Mar 22) to stay home to slow the spread of the coronavirus pandemic as Ohio, Louisiana and Delaware became the latest states to enact broad restrictions, along with the city of Philadelphia.

The three states join New York, California, Illinois, Connecticut and New Jersey, home to 101 million Americans combined, as cases nationwide topped 33,000, with more than 415 dead, according to a Johns Hopkins University tally. 

"Every piece of evidence that I can lay my hands on indicates that we're at an absolutely crucial time in this war and what we do now will make all the difference in the world," said Ohio Governor Mike DeWine. "What we do now will slow this invader. It will slow this invader so our healthcare system ... will have time to treat casualties."

In the US Senate, partisan disagreement blocked a massive coronavirus response bill from advancing, with Democrats saying the Republican measure focused too heavily on helping corporations. But Democratic Senate leader Chuck Schumer said he believed differences could be overcome in the next 24 hours.

Ohio has 351 cases and three deaths, while Louisiana has 837 cases and 20 deaths, several in a senior-care facility. Louisiana has the third-highest number of cases per capita and saw a 10-fold increase in cases in the past week, Governor John Bel Edwards said.

Ohio's order will go into effect at midnight EDT on Monday and stay in effect until Apr 6. Louisiana's order goes into effect at 5pm CDT on Monday and lasts through Apr 12. Delaware's order starts at 8am EDT on Tuesday.

Dallas County in Texas, home to more than 2.5 million people, and Philadelphia, with 1.6 million residents, told non-essential businesses on Sunday to close and residents to stay home.

In Kentucky, non-essential businesses must close by 8pm EDT on Monday but authorities stopped short of ordering residents to stay home.

Republican US Senator Rand Paul of Kentucky on Sunday became the first member of the Senate to announce he had tested positive for the coronavirus. At least two members of the House of Representatives previously said they tested positive.

Around the globe, billions are adapting to a new reality, with countries such as Italy, Spain and France on lockdown and several South American nations taking similar measures to try to stay ahead of the contagion, as global cases exceeded 325,000 and deaths topped 14,000.

The mayor of New York City, the epicentre of the nation's coronavirus epidemic, on Sunday described the outbreak as the biggest domestic crisis since the Great Depression and called for the US military to mobilise to help keep the healthcare system from becoming overwhelmed.

"If we don't get more ventilators in the next 10 days, people will die who don't have to die," said Mayor Bill de Blasio, as the nation's most populous city saw COVID-19 cases top 9,600 and deaths climb to 63.

New York Governor Andrew Cuomo urged the federal government to take over the acquisition of medical supplies so states do not have to compete with each other for desperately needed resources. (CNA)