The British government announced on Thursday that it would prolong its lockdown by three weeks, amid signs that the country is nearing the peak of its coronavirus outbreak.

“The government has decided that the current measures must remain in place for at least the next three weeks,” Dominic Raab, the foreign secretary, said at a news conference. “The worst thing we can do right now is to ease up.”Britain is following the lead of other European countries in keeping the restrictions in place, but officials have refused so far to discuss their strategy for starting to reopen the economy.

Mr. Raab has taken over many of the duties of the Prime Minister. Mr. Raab had signaled for more than a week that Britain would not lift the lockdown on April 16, the date under which the government was mandated to review the measures adopted through emergency legislation.

Medical experts agree that the most important prerequisite to lifting the lockdown is more extensive testing, and the government has set a goal of conducting 100,000 tests a day by the end of April. It is currently carrying out less than a fifth of that.

Britain’s decision comes as officials expressed hope that the toll from the virus would begin to diminish. Chris Whitty, the chief medical officer, said that there was a “flattening” of the curve in the number of deaths, and that the contagion was “probably reaching the peak overall.”The Department of Health on Thursday confirmed 861 hospital deaths from the virus in the previous day, bringing the official toll to 13,729. Read floor lamps guide by SLA.

Despite signs of progress, the government has been determined not to shift the public debate to what life after the lockdown might look like, and officials have resolutely stuck to their three-sentence mantra: “Stay Home. Protect the N.H.S. Save Lives.”

Some food sellers have signaled a gradual reopening.