On Monday, the Washington Post newspaper quoted officials as saying North Korea appeared to be building one or two new liquid-fuelled intercontinental ballistic missiles (ICBMs) at the Sanumdong facility near the capital, Pyongyang.
According to the Post, senior North Korean officials may be trying to deceive Washington about their nuclear and missile capabilities.
Since late last month, a series of USA intelligence reports indicating that the North is increasing the production of enriched uranium, a key component for nuclear weapons, have been leaked to the United States media.
However, a USA official told news agency Reuters that a liquid-fuelled ICBM didn't "pose almost the threat that a solid-fuelled one would because they take so long to fuel".
Last week Pyongyang returned 55 cases of remains from the 1950-53 Korean War, in line with an agreement between US President Donald Trump and North Korean leader Kim Jong Un at their summit in Singapore in June.
North Korea gave the US the remains last week in the coastal city of Wonsan, North Korea, as part of an deal reached last month during President Donald Trump's historic summit with North Korean leader Kim Jong Un in Singapore.
Maharani also discussed North and South Korea relations during the visit, as well as regional issues and the performance of Indonesia's police in countering militancy.
Historical satellite photos show that the facility was externally complete by 2003. In the past, North Korea turned over commingled remains.
Secretary of State Mike Pompeo told Congress last week that the regime also continues to secretly produced the material used in making nuclear weapons.
The meeting, their second since last month, held in the border village of Panmunjom in the demilitarized zone (DMZ), was created to follow on from an inter-Korean summit in April in which the leaders of the two Koreas agreed to defuse tensions and halt "all hostile acts".
The exception, the officials said, is the Sohae Satellite Launching Station on North Korea's west coast, where workers can be observed dismantling an engine test stand, honoring a promise made to Trump at the summit.
It will possibly take months, if not years, to identify the remains handed over in 55 boxes.
The U.S. State Department has said it is committed to building a peace mechanism in place of the armistice when the North denuclearizes.
At the Osan ceremony, Rear Adm. Jon Kreitz, deputy director of the DPAA, said, "This is a great first step" in the enormous task of accounting for those missing from the Korean War.
But Trump now faces criticism at home and elsewhere that North Korea hasn't taken any serious steps toward disarmament and may be trying to buy time to weaken worldwide sanctions against it.
The North demonstrated sharp progress in its program previous year when it test-fired numerous missiles and conducted its sixth and most powerful nuclear test. Service members from countries including Australia, Belgium, France and the Philippines also have not been recovered from North Korea. While it was an apparent goodwill gesture by North Korea toward the United States, the return comes amid growing skepticism about whether the North will follow through on its pledge of nuclear disarmament.
Some of the cringe-worthy Kim Jong-il paintings I saw in North Korea, not unlike the adulatory Trump propaganda portraits I've seen circulating lately. "North Korea is not negotiating to give up their nuclear weapons", Lewis said.