South Korean President Moon Jae In's visit to Pyongyang is the latest manifestation of rapidly thawing relations between the two Koreas, but pessimism persists over the prospects for progress on denuclearization in negotiations between North Korea and the United States.

In two days of summit talks with North Korean leader Kim Jong Un, Moon may have failed to convince him to show a clear roadmap to abandoning his nuclear weapons, as demanded by Washington.

[Pyeongyang Press Corps]

At the same time, uncertainty lingers over the future course of U.S. President Donald Trump's policy toward North Korea given the midterm congressional elections in November, which could swing the balance of power on Capitol Hill and affect the pace of denuclearization talks.

Moon has pledged to work as a "broker" between the United States and North Korea.

After their first-ever summit talks in Pyongyang on Wednesday, Kim and Moon signed a joint declaration including North Korea's promise to permanently dismantle its major nuclear complex in Yongbyon in the country's northwestern region, albeit conditionally.

North Korea will shut down the site if the United States takes reciprocal actions based on the agreement reached at their summit in June, the declaration said, with Pyongyang eager to win rewards for each step it takes in the denuclearization process.

At their June 12 summit in Singapore, Trump and Kim agreed that Washington will provide security guarantees to Pyongyang in exchange for "complete" denuclearization.

But U.S.-North Korea talks have been at a standstill since then, as Washington has complained that Pyongyang has not made enough efforts to achieve the agreement.

Kim might believe his latest commitment to closing the key nuclear complex is an adequate development to reopen negotiations with Trump, political experts say.

"A lack of progress at the inter-Korean talks would lessen the prospect of a second summit with the United States, and Kim Jong Un understands this," said Troy Stangarone, a senior director at the Korea Economic Institute in Washington.

The Pyongyang summit was "successful," which could help facilitate a second Trump-Kim meeting "before the end of this year," Stangarone said.

Later Wednesday, Trump tweeted the outcome of the Pyongyang summit was "Very exciting!"

Pyongyang has also adopted a conciliatory approach to Washington recently. At a military parade on Sept. 9 in its capital, North Korea did not display intercontinental ballistic missiles that can target the United States.

Earlier this month, the White House said Kim sent a letter to Trump to request a follow-up summit.

Other analysts, however, are skeptical about whether denuclearization negotiations will move forward, given that North Korea appears not to be serious about giving up its nuclear arsenal.

(Pyeongyang Press Corps)

"North Korea would want to keep discussions of denuclearization limited to the U.S.-North Korea track while trying to get economic benefits and movement on a peace agreement," said Malcolm Cook, a senior fellow at the ISEAS-Yusof Ishak Institute in Singapore.

"I do not think U.S.-North Korea relations will change," Cook said.

Indeed, the divergence in views over denuclearization between the United States and North Korea has shown no signs of receding.

The Rodong Sinmun, North Korea's most influential newspaper, said Tuesday, "The U.S. is totally to blame for the deadlocked DPRK-U.S. negotiations," referring to the country by its formal name of the Democratic People's Republic of Korea.

"The U.S. is stubbornly insisting on the theory of 'dismantlement of nukes first' which was rejected in the past DPRK-U.S. dialogues," the newspaper of the ruling Workers' Party of Korea said.

"For implementation of the DPRK-U.S. joint statement, the U.S. which is the other side should adopt a sincere approach," it added.

Some pundits, meanwhile, pointed out that the domestic political situation in the United States would prevent denuclearization talks from advancing.

"The midterm elections are an important factor" to gauge the outlook of U.S.-North Korea negotiations, said Stephen Nagy, a senior associate professor of politics at International Christian University in Tokyo and a fellow at the Asia Pacific Foundation of Canada.

"President Trump is likely to lose the House and possibly the Senate. Both would weaken him politically, making it much less likely that Trump can pursue quick denuclearization process with North Korea," Nagy added.

On Tuesday, Moon became the third South Korean president to visit North Korea. He is also the first foreign head of state or government to enter Pyongyang since Kim became the supreme leader following the death of his father Kim Jong Il in December 2011.

Moon, who took office in May 2017, was warmly welcomed, with thousands of citizens lining the streets holding pom-poms and flags.

A diplomatic source in Beijing warns that a sharp improvement in inter-Korean relations could have the adverse effect of delaying the denuclearization process.

South Korea may be willing to offer economic support to the North, whose economy has been sluggish against a backdrop of international sanctions aimed at hampering its development of nuclear weapons and delivery vehicles, the source said.

If Kim gets what he desires from Moon on that score, North Korea could "lose its motivation" to move forward with denuclearization, the diplomat added.

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