Kong, a Japan expert with limited experience in dealing with both Koreas, now has what’s considered an almost impossible task – reviving the six-party denuclearisation talks between China, the United States, North and South Korea, Russia and Japan.

He takes on the role at a time when the talks – once seen as evidence of Beijing’s growing diplomatic clout – have all but collapsed.

It is “a thankless job, with almost insurmountable challenges at the moment, where no one seems to be talking from the same page, and where the risks of failure are very high indeed”, said Kerry Brown, a former British diplomat.

Pundits believe North Korea’s reckless nuclear brinkmanship has not only advanced its weapons capabilities but it has also pit major powers – especially China and the US – against each other.

Despite Beijing’s repeated efforts to restart the talks, there is little sign of them resuming any time soon. Initiated by Beijing in 2003 and suspended since 2008 after North Korea boycotted further dialogue, neither Pyongyang nor Washington have shown a willingness to return to the negotiating table.

Compared to Foreign Minister Wang Yi, who was the first key negotiator for the six-party talks, or Wu, former ambassador to Japan and South Korea, 58-year-old Kong is largely unknown to many.

Kong is an ethnic Korean born in Heilongjiang and a fluent Japanese speaker who graduated from Shanghai Foreign Studies University after the Cultural Revolution.

He rose through the ranks at the foreign ministry, mostly dealing with Japanese issues, and held positions at Chinese diplomatic missions in Japan for more than a decade since the mid-1980s, according to the ministry website.

Kong was minister at the Chinese embassy in Japan between 2006 and 2011, serving as top deputy to three Chinese envoys to Tokyo, including Wang Yi, incumbent ambassador to Washington Cui Tiankai and Cheng Yonghua.

He later became Chinese ambassador to Vietnam, then head of the Asian affairs department in 2014.

Kong is believed to be proficient in Korean although he has never spoken the language in official settings, according to observers.

Seong-Hyon Lee, a research fellow at the Sejong Institute think tank, said that despite his Korean roots, there was a perception that Kong had not engaged with the South Korean community.

“Now, his new job requires him to have a lot of contact with South Koreans,” Lee said.

South Korean media noted that it would be the first time the top envoys on Korean affairs from Beijing and Washington could converse in Korean. Joseph Yun, an economist who was born in Seoul, was appointed in October as Washington’s new envoy for North Korean policy.

Kong was previously rumoured to be the replacement for Cheng, 63, who succeeded Cui in March 2010 and is now the longest serving Chinese ambassador to Japan.

Observers believe Kong will be dealing with a much more challenging and volatile Korean peninsula than his predecessor Wu, under whose watch North Korea launched five nuclear and 14 missile tests this year, including two intercontinental ballistic missiles last month.

Brown, a professor at King’s College in London, said Kong’s job would mainly involve dealing with a set of partners who had a chronic distrust of each other.

“No one on Earth probably has the diplomatic skills. He should be accorded wishes for best luck – he will really need it,” Brown said. “And it is not clear if he has the most crucial thing of all for his position – direct access into the Politburo and to President Xi. That, in the end, will prove decisive, because that is where the decisions will be made.”

Sun Xingjie, a Korean affairs expert from Jilin University, also said the North Korea nuclear crisis had become one of Beijing’s top diplomatic headaches, and it may need to overhaul its policy on the issue to reset the six-party talks.

“Diplomatic skills and experience will still count, but it doesn’t matter who does this job – I simply don’t think it will make much difference,” Sun said. “No one, including [US diplomacy guru] Henry Kissinger, would be able to bring North Korea back to the negotiating table if the purpose of the talks is denuclearisation.”

On Wu, observers noted that despite his decades of experience in Korean affairs, he had a mixed record when it came to diplomatic achievements. His career over the past 13 years saw some early success, with the beginning of the six-party talks, but ultimately those talks went nowhere, Brown said.

Lee, of the Sejong Institute based in Seoul, noted that Wu had met with a mixed response in South Korea from those who had personal dealings with him.

As Chinese ambassador to South Korea, Wu often made combative remarks on issues such as the Dalai Lama and Taiwan.

He was described by former South Korean nuclear envoy Chun Yung-woo, who later served as deputy foreign minister, as a hardline nationalist and China’s “most incompetent official”, according to a 2010 US diplomatic cable released by WikiLeaks.

“Wu was an arrogant, Marx-spouting former Red Guard who knows nothing about North Korea, nothing about non-proliferation, and is hard to communicate with because he doesn’t speak English,” Chun was quoted as saying in the leaked cable dated February 22, 2010.

Under Wu’s watch, Beijing’s ties with its Communist neighbour have sunk to an all-time low over nuclear issues, despite the strategic importance of the relationship.

In an apparent snub after Beijing imposed a sweeping ban on coal imports from North Korea, its leader Kim Jong-un – who has yet to meet Chinese counterpart Xi Jinping since he took power in 2012 – declined Wu’s scheduled visit to Pyongyang in April.