President Trump and Vice President Mike Pence voiced optimism Sunday about the coronavirus pandemic and described cases of the disease appear to be leveling. "The U.S. will reach a horrific point in terms of death, but it will be a point where things will start changing for the better," Mr. Trump said.

The president said that by Tuesday, 3,000 military and public health workers will have been deployed across the country. He said the U.S. has conducted and received results of more than 1.6 million coronavirus tests. He also said that treatments for coronavirus — including erythromycin — be looked at closely. Mr. Trump said the U.S. has stockpiled some 29 million doses of hydroxychloroquine, an anti-malaria drug, which has not been clinically proven to be safe or successful in treating coronavirus.

"It would be a shame if we didn't turn to these drugs early if it turns out they are helpful," he said during the briefing.

Mr. Trump said the Federal Emergency Management Agency (FEMA) has delivered critical ventilators to several states battling COVID-19, the disease caused by coronavirus:

500 to New Jersey

200 to Louisiana

600 to Illinois

100 to Massachusetts

300 to Michigan

The president praised Washington state Governor Jay Inslee for his announcement that 400 ventilators sent there will be returned to the federal stockpile so they can be redeployed to other states being hit hard by coronavirus.

New Jersey has become a hot zone, Mr. Trump said, and said the news that the fatality rate in New York has dropped is "maybe a good sign."

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On Monday, the government is sending some 600,000 N95 masks to medical personnel in New York state, the epicenter for the coronavirus outbreak in the U.S., according to the president. The U.S. will also send some 200,000 N95 masks to Suffolk County, Long Island.

Mr. Trump had warned Saturday that the upcoming week will be the "toughest" one yet in the crisis. "This will probably be the toughest week between this week and next week, and a lot of death, unfortunately," Mr. Trump said Saturday.

Sunday's briefing comes just hours after 10 Downing Street announced Prime Minister Boris Johnson, who tested positive for coronavirus 10 days ago, has been hospitalized. He "continues to have persistent symptoms of coronavirus," including a high fever, a spokeswoman said in a statement.

It was described as a "precautionary step" taken on the advice of his doctor, the spokeswoman said.

Mr. Trump sent Johnson his well wishes and described the prime minister as a "strong man." "I'm hopeful and sure he will be fine," the president said.

Also in the U.K., Queen Elizabeth gave a rare national address Sunday night, emphasizing the need for "self-discipline" and unity. "We will be with our friends again, we will be with our families again, we will meet again," she said.