Nursing a broken foot, Interior Secretary Dirk Kempthorne nevertheless trekked across the National Mall, chatted with school children and toured the Washington Monument on Tuesday, his first day on the job.

He seemed to relish his new job as he received a briefing on security improvements at the Washington Monument and chatted with tourists while visiting the 550-foot tall obelisk.

Kempthorne, the former Idaho governor, was sworn in as interior secretary on Friday.

In shirt sleeves, tie and wearing an Interior Department baseball cap, Kempthorne chatted with groups of schoolchildren at the base of the monument and then took the minute-long elevator ride to the top to the observation-deck level.

"That's an awesome sight," he remarked gazing westward over monuments honoring those who fought in World War II, Korea and Vietnam, as well as the Lincoln Memorial and, beyond that, Arlington National Cemetery.

A former senator, Kempthorne is not a newcomer to Washington. He said he had been to the top of the Washington Monument several times before and is particularly fond of the Lincoln Memorial.

As a senator for six years in the 1990s, he often would visit the National Mall and stop at the Lincoln Memorial and sit on its steps, said Kempthorne.

"What a great place to just think," he said.

Now, as interior secretary, he heads the department in charge of federal lands including the National Mall.

Despite a broken foot from a jogging mishap a week ago and a temperature in the high 80s, Kempthorne strode across the Mall to the famous obelisk, stopping frequently to chat with tourists and several groups of schoolchildren.

"What do you want to be when you grow up?" he asked a group of fifth-graders.

Kempthorne talked about riding techniques with a nearby Park Ranger on horseback, joked and posed for pictures with a group of 10th graders from Pulaski County, Va.

Kempthorne was brief privately by Dwight Pettiford, chief of the U.S. Park Police, about security improvements against potential terrorist attacks on the monument.

Security has been tightened in and around the Washington Monument, and anyone taking the elevator to the top of the obelisk must go through metal detectors. No longer can tourists walk up the monument and they can only walk down accompanied by a park ranger.

Kempthorne and Pettiford were peppered with questions by local reporters about another a security worry that has nothing to do with terrorists. There were three robberies and assaults at gunpoint within a 48-hour period in recent days on the Mall, which is patrolled by park police and long has had a reputation for safety.

"This is not acceptable," said Kempthorne of the recent attacks.

Pettiford and Vikki Keys, superintendent of the National Mall, said more park police are being shifted to the Mall area, especially at night when the recent attacks occurred.

The incidents underscore the two, sometimes conflicting, elements of the Mall — maintaining free, open access to the Mall and maintaining safety.

"It's a challenge," Kempthorne said.