Analysts say China is performing a delicate balancing act between Pyongyang and Seoul and is in a "unique" position to mediate between the two foes, as President Xi Jinping Thursday kicked off a state visit to South Korea.
The visit comes after a three-year gap since the last China-North Korea summit.
While about a dozen agreements ranging from finance and trade to the environment are expected to be sealed during the two-day trip, the nuclear issue on the Korean Peninsula is expected to top the agenda for Xi and South Korean President Park Geun-hye.
This is the first time that a Chinese president has visited South Korea before visiting the North while in office.
The last summit between the North and China was held in 2011 when late leader Kim Jong-il visited China. While Chinese Vice President Li Yuanchao met the North's current leader Kim Jong-un last July, the highest-level talks have yet to be realized.
"Pyongyang didn't observe the consensus reached at previous Six-Party Talks, leading to frustration among other parties involved, including China," said Zhang Xiao'an, an expert on Korean Peninsula studies and deputy head of the UN Association of China Wednesday.
North Korea's launch of a long-range rocket in December 2012 and its third nuclear test in February 2013 drew strong opposition from China, and its threat of another nuclear test in April once again triggered regional tension.
The North Wednesday fired two short-range projectiles into the sea off its east coast, which came after the firing of short-range, Scud-type missiles on Sunday, reported the Yonhap News Agency. It cited South Korean analysts as saying that Pyongyang might have been signaling displeasure over closer Beijing-Seoul ties.
Zhang attributed China's warming relations with South Korea to their common dispute with Japan over its militarist past, and more importantly "China is not going to leave Seoul entirely to Washington's arms."
"With the US rebalancing toward Asia, China's peripheral security situation is deteriorating, which makes Beijing attach more importance to denuclearization on the Korean Peninsula, because it can't let the US use this as an excuse to impose security threats in its neighborhood," Wang Sheng, a professor of international political studies at Jilin University in Changchun, Jilin Province, told the Global Times.
"Therefore, China wants Pyongyang to know that it can't only act in its own interests," he said.
Wang said he is optimistic at the impact of Xi's visit, which may exert "positive pressure" on Pyongyang. "Its concerns over closer China-South Korea ties might push it to reflect on its actions and make diplomatic efforts to reinforce communication with Beijing," he said.
Zhang shared similar views that the visit will prompt the North to woo China, given its reliance on China both politically and economically.
Beijing now describes its ties with Pyongyang as a "normal state-to-state relationship" rather than the "blood alliance" of decades ago. Despite the change of wording, analysts all agree that China is not carrying out a wholesale policy change.
Amid speculation over choice to visit Seoul first, China's deputy foreign minister Liu Zhenmin Tuesday told reporters that the trip does not target any third country.
"I haven't seen any fundamental change in Chinese foreign policy toward North Korea after Xi Jinping took office," Yoon Keunro, a research professor of political science at Seoul-based Hanyang University, told the Global Times. He said while South Korea wants changes in the North, China still wants to keep the status quo in its North Korea policies.
"Seoul holds extremely high expectations for Xi's trip, and is hoping China will tilt the balance completely to it. However, this is not happening," Wang said.
He noted that China is in a "unique position" as a mediator on the peninsula given its close ties with both the South and the North.
On Tuesday, South Korean Foreign Minister Yun Byung-se told parliament, "There will clearly be an expression of the commitment by the two leaders and their governments that North Korea's nuclear weapons will not be tolerated," reported Reuters.
However, in the Sino-South Korean joint statement released during Park's trip to Beijing last June, divergence remained an issue, with China stopping short of naming Pyongyang as the South did. The statement used the expression "denuclearization of the Korean Peninsula," which is in line with the North's claim that the denuclearization must apply to the entire peninsula, including the US nuclear umbrella.
It remains to be seen whether such an explicit expression will be included this time in the joint statement issued after Xi and Park's talks on Thursday, but analysts doubted China would agree to this due to its concern over the North.
In addition to talks on the Korean Peninsula nuclear issue, Xi's trip also highlights business cooperation.
It is reported that more than 250 Chinese business leaders, including heads of e-commerce giant Alibaba, telecommunication firm Huawei, Internet giant Baidu and China Southern Airlines, will be traveling with Xi to Seoul.
They will attend a business forum with their South Korean counterparts, including the heads of Hyundai, LG and Samsung.