Even though Congress has been on its August recess for weeks, Senator Tuberville’s hold on military appointments and promotions in an attempt to overturn a Pentagon policy relating to abortion is weighing on administration officials.

Mr. Tuberville has held up about 300 military appointments, including three of the eight members of the Joint Chiefs of Staff, who are currently serving in a limited capacity until they are formally confirmed by the Senate.

On Monday, at an event for an outgoing Navy admiral, Mike Golday, Secretary Austin criticized Mr. Tuberville’s hold as “unprecedented” and “unsafe,” saying that he has manufactured a problem for the military.

“Because of this blanket hold, starting today, for the first time in the history of the Department of Defense, three of our military services are operating without Senate-confirmed leaders,” Mr. Austin said.

Although Mr. Austin did not name Mr. Tuberville, the event was billed as a “relinquishment of command” ceremony rather than a more typical “change of command” ceremony.

“This sweeping hold is undermining America’s military readiness, it’s hindering our ability to retain our very best officers, and it is upending the lives of far too many American military families,” Mr. Austin said.

Ahead of the August recess, Mr. Tuberville also faced pressure from military families, with a group of military spouses hand-delivering a petition signed by hundreds of military families to Majority Leader Schumer and Minority Leader McConnell, saying they are “deeply concerned and personally impacted by Senator Tuberville blocking confirmation of senior military leaders.”

Democratic members of the Senate Armed Services Committee added to the pressure ahead of the recess by asking Mr. McConnell to pressure Mr. Tuberville to drop his hold.

Mr. Tuberville has shown no signs of relenting and is instead boasting about the attention he has been able to attract not only from other politicians but also from the press.

On Tuesday, Mr. Tuberville tweeted “Thank you” in response to an opinion piece in the Trussville Tribune titled, “Mainstream media attacks on Alabama Senator Tommy Tuberville just make him more popular.”

“Alabama supports the Constitution and the right to life,” Mr. Tuberville said.

Mr. Tuberville is protesting is the Pentagon policy of reimbursing the travel costs for military personnel who have to go out-of-state to receive an abortion, as well as those covered by its insurance.

A deputy press secretary at the Pentagon, Sabrina Singh, told reporters Tuesday that the Pentagon has no plans to give in to Mr. Tuberville’s protest.

“We’re not going to change our policy on ensuring that every single service member has equitable access to reproductive health care,” Ms. Singh said. “If you are a service member stationed in a state that has rolled back or restricted health care access, you are often stationed there because you were assigned there — it is not that you chose to go there.”

During a pro forma session of the Senate — a time when a single senator is required to call the Senate into session twice a week during recess in order to continue the recess — Senator Van Hollen told Punchbowl News that the only resolution he sees to this is in Senate Republicans urging Mr. Tuberville “to back down.”

“I haven’t seen them come down to the floor like Senate Democrats have and really put the pressure on,” Mr. Van Hollen said. “If that doesn’t work, we’ll have to look at other alternatives.”

While numerous reports have recounted some of Mr. Tuberville’s colleagues asking him in private to back down, none of his Republican colleagues have publicly come out against his hold on military appointments, and any resolution to the situation so far is out of sight.