US Defence Secretary Mark Esper has said he is open to reinstating the Navy captain removed from his post last week after asking for help with a coronavirus outbreak aboard his ship.

Captain Brett Crozier was relieved from his post as commander of the USS Theodore Roosevelt after sending a letter to Mr Esper pleading for help with an outbreak on the aircraft carrier. That letter was leaked to the media leading to his dismissal.

“We've taken nothing off the table,” Mr Esper told CBS News on Friday morning. “My inclination is always to support the chain of command, and to take the recommendations seriously.”

Mr Esper said that no further action will be taken against Captain Crozier until an investigation is completed.

CBS News's Gayle King asked if is ever OK to break the chain of command or protocol in cases where lives are in danger.

“Following the chain of command and maintaining operational security is very important in the military. There are always extreme cases where going outside of the chain of command makes sense, and that's why we want to see where this investigation leads,” Mr Esper replied.

“The last time I spoke to the chief of naval operations, we have over 90 ships at sea right now, and none of them have any problems, there are no infected crews, so I'm confident that the navy is taking prudent steps to maintain the health of our sailors and ensure our warships are ready to go.”

Since Captain Crozier's letter was leaked, the Roosevelt docked in Guam and sailors are being rotated off the ship into quarantine. As he left the ship he was cheered by those onboard who chanted his name.

The acting Navy secretary, Thomas Modly, has since been forced to resign after comments he made about Captain Crozier's actions came to light. Mr Modly referred to him as “stupid” and “naive.”