The U.S. military is working toward a “new normal” as it continues to grapple with the COVID-19 pandemic, Defense Secretary Mark Esper said.

“The long-term view is what do we do over the next six, 12, 18 months,” Esper said May 4 during a virtual event hosted by the Brookings Institution. “My view, the view of the chairman of the Joint Chiefs of Staff, the view of our commanders, is there will be a new normal that we will have to adapt to for a certain period of time.”

This period could last until a vaccine “we are confident in” is developed and available, Esper said.

During the COVID-19 crisis, tens of thousands of troops have been mobilized to help local and state response efforts. Troops are helping distribute food, supporting overwhelmed hospital staffs and more.

The military also has fought to contain the spread of the virus in its ranks, implementing travel restrictions and several other measures to protect service members, civilian employees and their families.

But the military also hasn’t stopped training, Esper said. Training is happening at the small-unit level, and leaders have adjusted and implemented safety measures based on the needs of each service, he said. DoD also is expanding its testing capacity and working to determine which units should be tested first.

“The challenge here is each service is different,” he said. “Each training area is different. Each training scenario is different.”

One of the challenges commanders face is transmission of the virus by asymptomatic carriers. “We’re experiencing very high rates in the military when it comes to asymptomatic transmissions,” Esper said.

Commanders continue to look at how they can safely train larger units, for example, a brigade combat team rotation to the National Training Center at Fort Irwin, California.

“The smaller the unit, the more capable you are of preserving the integrity of that unit that’s training,” Esper said. “The larger the unit, the more risk you absorb.”

But training cannot come to standstill, Esper said.

“The world remains a dangerous place,” he said. Many Americans are rightly focused at home because of the pandemic, he said, “but we’re still seeing all the same bad behavior we saw before” from America’s adversaries and competitors.

“We’re very cautious, and we’re also very conscious of what’s happening out there,” Esper said. “My watchword to the force is to remain vigilant. These are uncertain times, we don’t know how states or militaries will act, so we have to remain vigilant out there on the front lines.”