US Department of Defense Secretary Mark Esper says he is "not aware" whether the Pentagon received an intelligence report on the novel coronavirus that was completed last year, months before community spread of the virus was identified in the US and in military ranks.

Secretary Esper told ABC's This Week that he doesn't "recall" if the department had received a November assessment from the National Center for Medical Intelligence, a spying arm of the Defense Intelligence Agency, which reportedly briefed the National Security Council in December to determine the outbreak's impact to military readiness.

Before the World Health Organization declaration two weeks later, the agency predicted a global pandemic of Covid-19 at the end of February in a briefing to the Joint Chiefs of Staff.

He said: "We have many people who watch this closely. We have the premier infectious disease research institute in America, within the United States Army. So, our people who work these issues directly watch this all the time."

US military officials activated a global pandemic response plan on 1 February.

Secretary Esper said the Pentagon will issue new guidance for service members to wear face coverings this week, following new Centers for Disease Control and Prevention guidelines for every American to wear non-medical masks in public.

More than 1,200 military civilian staff and service members have tested positive for coronavirus.