Esper had been due to visit India, Pakistan and Uzbekistan between March 16 and 20 but decided "to remain in the US to help manage the DoD response" to the outbreak of Covid-19, the new strain of potentially deadly coronavirus spreading around the world, said Pentagon spokeswoman Alyssa Farah.

The US military has been largely spared so far by the coronavirus, with only a dozen or so cases confirmed among its forces deployed around the world.

But officials are trying to keep the Pentagon headquarters, where 20,000 service people and civilian employees work every day, free of the virus.

Civilian employees have been asked to do remote working from home while those who do show up are advised to practice "social distancing" and keep at least two yards (meters) away from their colleagues in the workplace.