US Secretary of State Mike Pompeo is in Pyongyang for a three-day visit. His mission is clear: Persuading or pressuring North Korea to dispel growing skepticism about its commitment to full denuclearization.

The most essential element of the mission should be getting the North to come up with a road map and timeline for removal of its nuclear arsenal and other weapons of mass destruction, including missiles and bio-chemical weapons.

Pompeo’s visit -- his third, but the first after the June 12 Singapore summit between US President Donald Trump and North Korean leader Kim Jong-un -- is crucial because negative factors that have surfaced recently have been casting doubt over the denuclearization the two leaders agreed on in their historic meeting.

The delay of Pompeo’s visit -- Trump said in Singapore that post-summit high-level talks involving his secretary of state would start the following week -- and the lack of any framework for systemic denuclearization talks have made one suspect that the North is resorting to its usual delaying or disruption tactic.

US news media raised concerns over the possibility of the North’s denuclearization promise going in the opposite direction, quoting government intelligence officials. They said that the North is seeking to conceal its nuclear capacity, including the number of warheads, and continuing or building up its nuclear and missile capacities. Suspected activities include increasing production of enriched uranium and ballistic missile transport vehicles.

The North also did not take any follow-up action to Kim’s promise -- made to Trump in Singapore -- that it would dismantle its main missile engine test facility.

This means that the North has only showcased the destruction of a nuclear test site and halted new nuclear and missile tests despite all the fanfare surrounding Kim’s two summits with President Moon Jae-in and the Singapore meeting with Trump,

All these should raise concern that the US -- as with its past administrations -- is playing into the hands of the North. The change of denuclearization terms the US has been setting also add to skepticism about its will to achieve early denuclearization.

After Trump failed to get Kim to accept complete, verifiable and irreversible dismantlement of the North’s nukes at their Singapore meeting -- they only agreed to “complete denuclearization”-- US administration officials mentioned “permanent, verifiable and irreversible dismantlement.

Now US administration officials have devised a new concept: A State Department spokesperson said that Pompeo, who plans to visit Tokyo on his way home, will discuss with his Japanese and South Korean counterparts “final, fully-verified dismantlement.”

There is no problem if US officials devised FFVD as an effective alternative to CVID in consideration of the fact that the North has been very sensitive to the term and the Libyan-style unilateral denuclearization once advocated by hard-line national security adviser John Bolton. It is a big problem, however, if the US were to opt for a lower level of denuclearization.

In relation to this, Bolton provided a good guideline. In an interview, he said that he has come up with a program to dismantle the North’s nuclear and biochemical weapons and missiles within one year.

Pompeo’s ongoing visit to Pyongyang should yield at least a road map reflecting such a timeline, for which early action by the North to report and allow inspection of all related facilities is essential.

Trump, who had insisted that he would not repeat the same mistakes made by his predecessors, said in a tweet that conversations with North Korea “are going well” and that all of Asia is thrilled that he prevented war with the North.

Not only Asians but also the whole world will soon know whether Pompeo left Pyongyang with a substantial outcome from his talks with the North Koreans.

The worst-case scenario would be Pompeo returning home only with the remains of American soldiers who were killed in the Korean War. The recovery of what Trump has called “fallen heroes” is not unimportant, but it still would only be an auxiliary achievement. Overall, the talks will be meaningless without real progress in the denuclearization process.