Pentagon leaders said Tuesday morning that the coronavirus could last months.

"I think we need to plan for this to be a few months long at least," Secretary of Defense Mark Esper said, with Chairman of the Joint Chiefs of Staff Gen. Mark Milley saying that reports and models indicate this could last three months.

Their comments contrast with those of President Donald Trump, who said Monday that the country "will again, and soon, be open for business — very soon — a lot sooner than three or four months."

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As the president expresses a strong interest in reopening the country in the near future, the Pentagon is bracing for a coronavirus crisis that will last at least a few months.

"We have to be prepared to address it as long as the country needs us," Secretary of Defense Mark Esper said during a town hall meeting on Tuesday.

"I think we need to plan for this to be a few months long at least, and we are taking all precautionary measures to do that, to be in it for the long haul."

Chairman of the Joint Chiefs of Staff Gen. Mark Milley concurred, saying that all the reports indicate that "you are looking at eight to 10, maybe 12, weeks — call it three months."

Milley added that "some of that depends on what we do as a nation to mitigate it, to flatten the curve, so to speak."

The coronavirus that first appeared in China has spread to more than 395,000 people worldwide and claimed more than 17,000 lives. The US, the third-worst-hit country, has reported more than 46,000 cases and well over 500 deaths.

The Department of Defense reported 174 cases among US military personnel on Tuesday, more than double what it was Friday. The Pentagon also reported 59 cases among civilian personnel, 61 cases among dependents, and 27 cases among contractors.

As the numbers continue to grow, President Donald Trump has been pushing for the US to reopen.

"America will again, and soon, be open for business — very soon — a lot sooner than three or four months," Trump said during a Monday evening press briefing.

"Our country wasn't built to be shut down," he added.

The Department of Defense announced Monday that the Health Protection Condition (HPCON) for the Pentagon reservation has been increased to "Charlie," the second-highest level, and increased restrictions have been put in place for the building.

"We're going to telework as long as necessary to ensure we are beyond the coronavirus crisis," Esper said Tuesday. "It's going to be weeks for sure, maybe months."

"At the end of the day, in a period of months, we will get through this," he added in closing remarks.