Stephen Miller, a senior adviser for policy to President Donald Trump and his senior speechwriter, says he is COVID-19 positive - bringing to at least 19 the number of people working at or with the White House that have the disease.

"Over the last five days I have been working remotely and self-isolating, testing negative every day through yesterday," Miller said. "Today, I tested positive for COVID-19 and am in quarantine."

Miller's wife, Katie, the communications director for vice president Mike Pence, tested positive for COVID-19 in May.

There are now more confirmed COVID-19 cases in the White House than there have been in New Zealand, Taiwan and Vietnam combined over the past seven days.

In addition, three Republican Party senators, one former Republican Party governor and three photographers assigned to the White House have the illness. On Tuesday, it was reported all members of the U.S. Joint Chiefs-of-Staff, including its chairperson Gen. Mark Milley, had gone into voluntary quarantine after coming into contact with U.S. Coast Guard Admiral Charles Ray who tested positive Monday.

It isn't known how many White House staffers have tested positive from COVID-19 because it refuses to say.

Senior White House staffers and top Republican Party operatives testing positive for COVID-19 are Miller, press secretary Kayleigh McEnany, counselor to president Hope Hicks, Nicholas Luna, one of Trump's personal assistants, Trump's reelection campaign manager Bill Stepien, chairperson of the Republican National Committee Ronna McDaniel, and Trump's military aide.

In addition, at least eight others and two gardeners have been confirmed COVID-19 positive.

Some 400 people work at the White House. Three journalists have also taken ill after attending press briefings by McEnany.

Other top Republicans taken ill from COVID-19 since Sept. 26 are former New Jersey Gov. Chris Christie, Sen. Mike Lee, a Republican from Utah, Sen. Thom Tillis, a Republican from North Carolina and Sen. Ron Johnson from Wisconsin.

Trump checked himself out of the Walter Reed National Military Medical Center Monday evening with the consent of his team of physicians. Trump is classified as an active COVID-19 patient being treated for the disease and still contagious.

While the White House and the physician to the president, Dr. Sean Conley, has refused to reveal when Trump had his last negative COVID-19 test, other doctors have said Trump will remain infectious this week.

Clinical studies have shown that people with COVID-19 have "a low but real possibility of infectiousness" between seven and nine days after falling ill.