WASHINGTON (NEXSTAR) – Stephen Miller, President Donald Trump’s senior adviser and speechwriter, tested positive for the coronavirus Tuesday.

A senior administration official said Miller had previously tested negative as White House officials have tried to contain an outbreak on the complex that has infected Trump, the first lady and more than a dozen other aides and associates.

“Over the last 5 days I have been working remotely and self-isolating, testing negative every day through yesterday. Today, I tested positive for COVID-19 and am in quarantine,” Miller said in a statement.

Miller is an architect of the president’s “America First” foreign policy and restrictive immigration measures.

His wife, Katie Miller, who serves as communications director to Vice President Mike Pence, previously had the virus and tested negative after the last time she saw him. Katie Miller had been in Salt Lake City with Pence, where he is preparing to debate Democratic vice presidential nominee Kamala Harris, but she left as soon as she found out about her husband’s diagnosis.

Miller is the latest in a string of positive diagnoses at a White House where the president, still likely contagious, has returned to continue working.

Criticism that Trump underestimated the the virus and failed to prepare the nation has become a central narrative in Democrat Joe Biden’s campaign to deny the president a second term. Some academics project that the death toll from COVID-19 could double by the beginning of next year, to around 400,000.

Trump, infected with the coronavirus and hospitalized over the weekend, is now back at the White House. He has tweeted “Don’t be afraid of Covid,” adding: “Don’t let it dominate your life. We have developed, under the Trump Administration, some really great drugs & knowledge.” He says he plans to return to the campaign trail.

The Associated Press contributed to this report.