Texas on Friday became the largest US state to begin easing coronavirus lockdown measures despite reporting a single-day high in deaths.

Stores, restaurants, movie theaters, malls, museums and libraries were allowed to reopen in the Lone Star State but with limited occupancy - just 25 percent of their capacity.

Texans will also be allowed to participate in outdoor sports provided no more than four players take part at one time.

But Governor Greg Abbott sounded a note of caution, tweeting that "Texans should continue to practice social distancing" and follow health guidelines.

"Face coverings are not mandatory, but encouraged to protect the lives of individuals at high-risk," he said.

Public swimming pools, bars, gyms, beauty salons, massage establishments, bowling alleys, video games arcades and tattoo parlors remain closed.

More than 28,000 cases of coronavirus have been reported in Texas, according to the state health authorities, and there have been 782 deaths.

Fifty COVID-19 deaths were reported in the state on Thursday, the most since the outbreak began in mid-March, and 1,000 new cases, the largest single day number since April 10.

The most cases - over 6,000 - have been reported in Harris County, the most populous in Texas and home to Houston, the largest city in the state with a population of 2.3 million.

With more than one million confirmed cases, some 63,000 of them fatal, the United States has more infections and deaths than any country in the world.

The number of cases has been on the decline in some of the hardest-hit states such as New York, New Jersey, Louisiana and Florida.

But the daily count of new cases nationwide has been holding steady at 25,000 to 30,000 and the United States recorded more than 2,000 deaths on Thursday for the third day running, according to a tally by Johns Hopkins University.