BEIJING (AFP) - China and South Korea agreed to push for denuclearisation of the Korean peninsula, Chinese President Xi Jinping said on Thursday at a summit with South Korea's leader focused on North Korea's nuclear programme.

"We on both sides consistently agree to continue to realise the denuclearisation of the Korean peninsula and firmly protect peace and stability on the peninsula," Mr Xi said at a joint appearance with the South's Park Geun-Hye.

Ms Park arrived in Beijing on Thursday for summit talks to be dominated by Pyongyang's nuclear programme, seeking to push China to do more to bring its wayward ally North Korea to heel.

China has previously supported denuclearisation but tended to prioritise regional stability, for decades acting as the sole major ally and economic lifeline to the unpredictable North.

Washington and Seoul have made it clear they will never accept the idea of North Korea as a nuclear state, and insist Pyongyang must show a tangible commitment to abandoning its nuclear weapons if it wants substantive talks.

Both have pressured China to use more of its leverage to rein in Pyongyang.

The North appears to have moderated its stance after a series of bellicose statements and gestures in recent months against Seoul and Washington, including threats of nuclear war.