Chinese President Xi Jinping has met with his South Korean counterpart for talks, seen by some as a snub to China's long-standing ally North Korea. Pyongyang staged a series of rocket tests in the run up to the meeting.
Xi arrived in Seoul on Thursday for talks that were expected to broach North Korea's political program and reaffirm both countries' goal of a nuclear-free Korean peninsula.
The Chinese leader held a meeting with South Korean President Park Geun-hye, who took office last year.
In a joint statement issued after a summit in Seoul, the two leaders said the Korean peninsula should become free of nuclear arms.
The two Asian countries also reaffirmed their opposition to any further nuclear tests by Pyongyang.
Xi and Park also agreed on concluding negotiations for a free trade deal by the end of the year and take measures to spur offshore use of the yuan and investment in the Chinese markets.
The two countries already have a strong commercial relationship with two-way trade worth an estimated $230 billion (170 billion euros) annually.
"China and South Korea as neighbors must jointly respond to challenges in the security environment, while sharing the opportunity for development that peace and stability of the region offers," said Xi, in an article that was carried by major South Korean newspapers on Thursday.
The state visit has been seen by some analysts as a snub to North Korea, with Beijing traditionally Pyongyang's most important political ally. Xi's choice to meet Park represents something of a departure from protocol, which Chinese president normally making the North their first stop on visits to the peninsula.
Display of irritation?
In the week leading up to the visit, North Korea fired seven short-range missiles, two of which were launched of its eastern coast on Wednesday. That move that has been interpreted by some observers as a fit of pique by the leadership in Pyongyang at the perceived rebuff.
"No previous Chinese leader has put South Korea before and above the North like this," Aidan Foster-Carter, an expert on North Korea for Leeds University, told the AFP news agency.
While Xi has already met South Korean President Park Geun-Hye four times, he has yet to sit down with North Korean leader Kim Jong-Un.
However, Chinese Foreign Ministry spokesman warned reporters ahead of the visit not to read too much into the fact that Xi was visiting the South first.
There was some diplomatic success for North Korea on Thursday as Tokyo said it would revoke some of the unilateral sanctions that it has imposed on North Korea, after progress was made in discussions about the Cold War kidnappings of Japanese citizens.
shs, rc/kms (AFP, dpa,Reuters)