Reports that North Korea has started dismantling facilities at a rocket test site are consistent with a commitment Pyongyang made at a summit last month, but it must go further and fully denuclearize, U.S. Secretary of State Mike Pompeo said on Tuesday.

Pompeo said after meetings with his Australian counterpart in California that the United States had been pressing North Korea to allow inspectors on the ground when the Sohae site was dismantled, something also "consistent" with a commitment by North Korean leader Kim Jong Un at the Singapore summit in June with U.S. President Donald Trump

Asked at a joint news conference what further steps were needed by North Korea, Pompeo said: "They need to completely, fully denuclearize. That's the steps that Chairman Kim committed to."

As Pompeo spoke in California, Trump told an audience of U.S. veterans in Kansas City he hoped the remains of American soldiers killed in the 1950-53 Korean War would be returned by North Korea soon - another agreement the president has touted from the summit that has been slow to materialize.

"As you may know we're also working to bring back the remains of your brothers in arms who gave their lives to Korea," Trump said. "I hope that very soon these fallen warriors will begin coming home to lay at rest in American soil."

Washington-based think tank 38 North said on Monday that satellite images of the Sohae Satellite Launching Station from last week indicated North Korea had begun dismantling a building used to assemble space-launch vehicles and a nearby rocket engine test stand used to develop liquid-fuel engines for ballistic missiles and space-launch vehicles.

A 38 North report said it was a first step toward fulfilling a pledge made at the summit and a significant confidence-building step amid growing questions about North Korea's willingness to give up a nuclear weapons program that threatens the United States.

U.S. officials have repeatedly said North Korea has committed to abandoning the program, but Pyongyang has offered no details as to how it might go about this.

It has also appeared to drag out discussions on the promised return of American soldiers' remains. Pompeo said on July 18 that progress had been made on this issue and that he thought the first batch would be returned in the next couple of weeks.

Washington hoped North Korea would return about 50 sets of remains within two weeks but details were still uncertain, a senior U.S. defense official said last week.