North Korea has been making what critics say are "cosmetic concessions" to the United States in an apparent effort to keep President Donald Trump engaged in negotiations and court him toward declaring an end to the Korean War, which is technically ongoing as the conflict was halted by a truce.

While returning some of the remains of American troops who died in the 1950-1953 conflict and starting to dismantle a missile engine testing site, North Korea has been stepping up calls for an official declaration of the war's end. Such a move, with the United States and other parties, would be seen by Pyongyang as a first step toward establishing a peace on the Korean Peninsula that would guarantee the North's security.

At a 27-member regional security meeting Saturday in Singapore, North Korean Foreign Minister Ri Yong Ho criticized U.S. Secretary of State Mike Pompeo for not responding to Pyongyang's urging to declare an end to the war, a measure he called "a very basic and primary step for providing peace on the Korean Peninsula."

Washington, however, is reluctant to issue such a statement without Pyongyang taking credible steps toward denuclearization, key of which would be a full and honest account of its nuclear weapons, related facilities and fissile materials, subject to verification by organizations such as the International Atomic Energy Agency.

Analysts caution that declaring an end to the conflict -- though not legally binding -- would pave the way for relevant parties to replace an armistice with a peace treaty, a development that could lead to an eventual withdrawal of U.S. forces from South Korea.

"This is what North Koreans really want," said Sue Mi Terry, senior fellow for Korea at the Center for Strategic and International Studies, a Washington think tank. "That's what they are pressing for before denuclearization."

At a meeting in April, South Korean President Moon Jae In and North Korean leader Kim Jong Un agreed to work trilaterally with the United States or quadrilaterally with the U.S. and China toward declaring the war's end this year, as well as turning the armistice into a peace treaty and establishing a permanent peace regime.

The armistice was signed on July 27, 1953, by the U.S.-led United Nations Command, North Korea and the Chinese People's Volunteer Army.

Speculation has been swirling that the leaders of the two Koreas, the United States and China may issue a war-ending declaration when world leaders gather for the U.N. General Assembly in September, with South Korean Foreign Minister Kang Kyung Wha referring to such a possibility.

If realized, it would be a "political declaration" aimed at facilitating the denuclearization of the Korean Peninsula, Kang was quoted by Yonhap News Agency as telling South Korean lawmakers on July 25.

Such a remark -- together with a Trump tweet Thursday that he looks forward to seeing Kim "soon" -- has raised speculation that Kim may have a second meeting with Trump on the occasion of the North Korean leader's possible debut on the world stage in New York.

But analysts say that in order for Kim to have a second summit with Trump, Pyongyang must go beyond confidence-building measures, given concerns that the two leaders just meeting without progress on denuclearization would amount to a de facto U.S. recognition of North Korea as a nuclear state.

For Kim to meet Trump again following their historic summit in June in Singapore, "He would have to give something beyond just returning the remains of U.S. servicemen," Terry said. "I think it has to be something to do with a declaration (of the North's nuclear weapons program) or the disablement of (nuclear) facilities."

She dismissed the recent start of dismantling at the Sohae Satellite Launching Station and the handover of 55 American troop remains as "cosmetic concessions" to mask the lack of progress since Kim committed to "complete" denuclearization in the first-ever U.S.-North Korea summit.

A U.N. experts' report seen by Kyodo News on Friday said North Korea has continued with its nuclear and missile programs in breach of U.N. bans, citing activity at the country's main nuclear complex.

Some analysts say North Korea is targeting Trump by presenting not a timeline or road map for denuclearization but symbolic measures such as a war-ending declaration and the recovery and repatriation of the remains of an estimated 5,300 fallen American service personnel.

Such symbolic actions could allow the president, who has not ruled out the possibility of reducing U.S. troop levels in South Korea, to claim victory in the run-up to the U.S. midterm elections in November.

The remains issue "is obviously of great importance to the United States because it's what's due to our fallen warriors, but it has nothing to do with denuclearization," said Bruce Klingner, the senior research fellow for Northeast Asia at the Heritage Foundation, a Washington think tank.

"I think that by appealing to Trump directly they would like to decouple the president from Pompeo and (national security advisor John) Bolton because they figure they'll get a better deal out of Trump because he's more interested in the symbolism than substance," Klingner said.

Given North Korea's track record of using denuclearization talks to extract aid and other concessions while covertly continuing development of nuclear weapons and ballistic missiles, other scholars have also pushed Pyongyang to file a declaration of its weapons programs as a first step toward complete, verifiable and irreversible denuclearization.

"A complete and correct declaration is the bedrock of any effective verification program," said William Tobey, a senior fellow at the Harvard Kennedy School Belfer Center for Science and International Affairs.

"Given the fundamental importance of this problem to international security, we can't afford a situation in which the North pretends to denuclearize and we pretend to believe them," Tobey said.