WASHINGTON — Defense Secretary Lloyd Austin will decide in the next few days whether to recommend that President Joe Biden make coronavirus vaccinations mandatory for the country’s 1.3 million active-duty troops, military officials said, signaling a major move by the administration to harden the country’s defenses against the highly contagious delta variant.

Biden announced last week that all federal employees and on-site contractors must be vaccinated against the coronavirus or be required to submit to regular testing and other measures. The requirement extended to the 766,372 civilians working for the Defense Department but not active-duty service members.

That could soon change, administration and military officials said Tuesday. Austin, who recently returned to the United States from a trip to Asia, has asked the military services to report on how and when they would go about putting a mandate in place. Austin has previously said that he would not be comfortable with a mandate until the vaccines are fully approved by the Food and Drug Administration, but officials and executives across the board are rethinking their position as the delta variant surges.

More on the COVID-19 pandemic

“He’s not going to let grass grow under his feet,” Pentagon spokesperson John Kirby told reporters during a news conference Tuesday. “We’ll have more to say in very short order here.”

Because the health and justice authorities that govern service members are different from those that apply to other federal workers, the decision will ultimately be made by the president, who must grant a waiver to the Defense Department to make vaccines mandatory. Military leaders cannot require the shots, because the coronavirus vaccines are not fully approved and are authorized only on an emergency basis.

Advertising

About 64% of active-duty military members are fully vaccinated, above the 60% of Americans over 18 who are fully vaccinated. But for the military, the rate is unacceptably low, raising issues of readiness should cases rise among service members. It is also difficult to deploy troops who have not been vaccinated to countries with stringent local restrictions.

Beyond readiness, a big part of the push for a mandate for the military centers on the belief that service members could set an example for their families and friends in states where vaccine hesitancy has been higher.

“When people see that these guys got the vaccine and nothing happened to them, that could be decisive,” said Ezekiel J. Emanuel, a bioethicist at the University of Pennsylvania who advised Biden during his transition.

“People admire our military,” he said. “They can serve as a positive example.”

This article originally appeared in The New York Times.