Weeks after a scathing government report concluded that the U.S. Park Police had lost track of thousands of handguns, rifles and machine guns, the agency has accounted for 98 percent of its arsenal, officials told a congressional oversight panel Friday.

The report, officials said, represented a snapshot in time when the police force was between inventory management systems; the force did not actually lose any weapons, they said. All of its weapons have since been accounted for except those belonging to three officers, one of them overseas with the military and the other two on leave, they said.

“The accountability of weapons used by our law enforcement personnel is of critical importance, and we take the issues raised here very, very seriously,” Jonathan B. Jarvis, who heads the National Park Service, told subcommittee members of the House Natural Resources and Oversight and Government Reform committees. After the hearing, he said: “There are no missing weapons.”

Lawmakers remained skeptical, grilling federal park officials about a report released by the Interior Department’s inspector general’s office in June that not only discovered thousands of weapons unaccounted for but also noted that similar problems were found in 2011, 2009 and 2008 — and were never fixed.

“Are we going to be back here five years from now and the situation’s going to be the same?” asked Rep. John J. Duncan Jr. (R-Tenn.) “Or are you just going to go back to your offices and laugh?”

Rep. Jason Chaffetz (R-Utah) chastised Jarvis and U.S. Park Police Chief Teresa Chambers for the “ongoing problem” and asked for weapon and ammunition inventories, historical purchase data and future purchase projections to be provided to the committees.

“If the president wants some gun control, perhaps he should start with the Park Police,” Chaffetz said.

Chambers defended her department throughout the hearing. “At every step along the way, extreme action was taken,” she said.

She added that during the inspector general’s investigation, she could not say “with certainty” that all weapons had been accounted for. “But we can say that now,” she told lawmakers. “It has been reconciled.”

Jarvis, too, defended the Park Police. “We have an inventory management issue, and that’s exactly what the IG found. They came in, they could not reconcile the weapons that they saw in U.S. Park Police possession against what should be a computerized database.”

More than 600 officers serve with the Park Police, patrolling National Park Service property across the nation, including the Mall and many of Washington’s monuments and acres of parkland.

The 2013 review began in part when an anonymous tipster said Park Police officers were improperly taking weapons home. The report documented two such instances, but one of them was disproved after the report’s publication, when a former chief of the Park Police produced paperwork showing that he had properly taken his weapon with him to a new federal job.

“Commanders up to and including the chief of police have a lackadaisical attitude toward firearms management,” wrote Mary L. Kendall, the deputy inspector general. “Historical evidence indicates that the indifference is a product of years of inattention to administrative detail.”

Ian R. Glick, chairman of the U.S. Park Police’s Fraternal Order of Police, called the inspector general’s report “reckless” and “subjective” and said it undermined the public’s confidence in the police force.

Lawmakers were frustrated with the agency, and some wondered whether an inventory of its ammunition would bring to light the same concerns.

“They’ve got to get their act together,” said Rep. Rob Bishop (R-Utah). “This is not the way to run a government agency.”

Chaffetz also brought up the recent vandalism at the Lincoln Memorial, which is guarded by Park Police, calling it “totally and wholly unacceptable that we don’t have the adequate control on something so precious and so visible, so close to the White House.”