Washington — In a letter to the nation's governors on Thursday, President Trump said his administration is working on new guidelines to help state and local policymakers determine whether they should maintain, increase or relax social distancing measures they've put in place to mitigate the fallout from the coronavirus.

On March 16, the White House issued guidelines about how Americans can "slow the spread" of the virus over a 15-day period, but governors and local officials have been making decisions about closing businesses and schools for themselves. In Washington, D.C., the mayor has ordered the closing of all non-essential businesses until at least April 24.

Mr. Trump has established a goal of Easter Sunday, April 12, for returning Americans to work and the economy to some version of normalcy, although he concedes that won't be possible everywhere, and public health experts warn Easter is much too soon to consider relaxing measures to stop the spread of the virus.

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"There is still a long battle ahead, but our efforts are already paying dividends," the president said in his letter Thursday. "As we enhance protections against the virus, Americans across the country are hoping the day will soon arrive when they can resume their normal economic, social and religious lives."

"In furtherance of this shared goal, my administration is working to publish new guidelines for state and local policymakers to use in making decisions about maintaining, increasing or relaxing social distancing and other mitigation measures they have put in place," he continued.

The president said expanded testing will inform those criteria, which will be crafted in coordination with public health officials and scientists, and used to classify individual counties as high-risk, medium-risk or low-risk areas.

"As testing gives us more information about who has been infected, we are tracking the virus and isolating it to prevent further spread," Mr. Trump wrote. "This new information will drive the next phase in our war against this invisible enemy."

Mr. Trump has expressed impatience by the economic toll the virus is inflicting, as businesses around the country shutter. Weekly jobless claims soared Thursday to roughly 3.3 million, the greatest one-week increase on record.

Meanwhile, governors and hospitals are urging the president to use his full authority under the Defense Production Act to produce ventilators, masks and other needed equipment. The president has been reluctant to do so, suggesting companies are ramping up production voluntarily, and telling governors to try to get the equipment on their own first.

But the governors have pointed out to the president they're competing against the federal government's bids for much-needed ventilators and other equipment.