China should play an active role in managing the six-party talks on North Korea's nuclear programme, which could resume after Pyongyang sent a special envoy to Beijing, analysts say.
"The process will lose its authority if it still allows any party to enter or withdraw arbitrarily without cost," said Professor Wang Fan , a specialist on the North Korean nuclear issue at China Foreign Affairs University.
Last week, North Korean leader Kim Jong-un sent special envoy Vice-Marshal Choe Ryong-hae to Beijing. Choe told President Xi Jinping that Pyongyang was willing to take steps to rejoin the long-stalled six-party talks on its nuclear weapons programme.
Pyongyang walked away from the talks in 2009, and although analysts doubt they will resume soon, recent and upcoming diplomatic activity between the different countries raises questions about how their new leaders will approach the issue. The talks involve China, the two Koreas, Russia, the US and Japan.
Wang said China should suggest that all six parties agree on how to maintain the authority of the talks with incentives and penalties, including establishing a peaceful agreement to prevent North Korea being invaded and measures against those who failed to uphold the aims of achieving a nuclear-free Korean peninsula and regional security.
Beijing, Pyongyang's only remaining diplomatic ally, finally lost patience after the Stalinist state's young leader ordered a long-range rocket test in December, weeks after Xi gained control of both China's Communist Party and the military at the party's 18th congress.
Shi Yongming, an expert on Sino-North Korean ties, told the Beijing Times top-level lines of communication between the two countries had been suspended since Pyongyang staged its third nuclear test in February, which explained why a special envoy came to Beijing last week.
China also sided with the US in imposing sanctions against its ally in January, with state-owned Bank of China closing the account of a North Korean bank accused by Washington of supporting its nuclear programme.
Wang said China had sent advance notice to the other four nations in the six-party talks that Choe would visit Beijing.
Another expert on Korean affairs, Gao Haikuan , said Kim Jong-un realises China "is his only trusted friend".
"China is also the ideal conduit for South Korean President Park Geun-hye and US President Barack Obama to convey their messages to Kim, helping them to understand each other better," Gao said.