Esper has received a verbal update on the investigation into the outbreak on the USS Theodor Roosevelt from the Navy's top officials, and was awaiting a written report before he makes any decision, Pentagon spokesman Jonathan Hoffman said.

But news reports said Acting Navy Secretary James McPherson and Chief of Naval operations Admiral Michael Gilday had recommended that Brett Crozier, who was removed for publicly sounding the alarm over the outbreak, be reinstated.

And pressure built from members of Congress to restore Crozier back to the Roosevelt.

Crozier was removed by then-Acting Navy Secretary Thomas Modly after writing an unclassified letter to his superiors -- which leaked to the media -- spelling out the threat an initial handful of shipboard COVID-19 infections posed to the entire 4,800-member crew.

In the March 30 letter, he urged his leaders to allow him to evacuate and sterilize the vessel at dock in Guam to avoid a potentially deadly outbreak.

"The spread of the disease is ongoing and accelerating," Crozier wrote. "We are not at war. Sailors do not need to die."

With cases nearing 100, on April 1 the Navy began evacuating the ship, but a day later Modly fired Crozier for allegedly taking his concerns public, breaking the chain of command and exposing a weakness in the US defense force.

Crozier "demonstrated extremely poor judgment in the middle of a crisis" Modly said, accusing him of creating "unnecessary" panic.

Days later, Modly himself resigned for mishandling the issue, including a forceful, profanity-laced speech to the Roosevelt crew in which he accused Crozier of "betrayal."

Since then, the entire crew has been tested and 840 -- including Crozier himself -- have come up positive for coronavirus. Several were hospitalized and one died.

In Congress pressure built on Esper to reinstate Crozier.

"While Captain Crozier's actions at the outset of the health crisis aboard the TR were drastic and imperfect, it is clear he only took such steps to protect his crew," Adam Smith, chair of the House Armed Service Committee, said in a statement.

"During this time of crisis, Captain Crozier is exactly what our Sailors need: a leader who inspires confidence," he said.