China on Friday urged restraint ahead of the launch of a North Korean rocket, after Tokyo said it was readying its missile defence systems to shoot it down if it posed any threat to Japan.
"All parties should keep calm and exercise restraint and refrain from actions that would complicate the issue," foreign ministry spokesman Hong Lei told reporters.
The nuclear-armed North has announced it will launch a rocket in mid-April to put a satellite into orbit, a move that the United States, South Korea and other nations see as a pretext for a long-range missile test banned by the UN.
The move by North Korea's new leadership has set off alarm bells across the region, including in China -- Pyongyang's closest ally -- which last week expressed concern over the launch and urged restraint.
Hong said Beijing had made immediate contact with North Korea, Russia, Japan, the United States and other parties when it found out about the planned rocket launch.
"We stressed that peace and stability in the Korean peninsula and Northeast Asia is (in) the common interest of all parties and also their common responsibility," he said.
Japan's defence minister said Friday he had ordered officials to ready missile defence systems to shoot down the rocket if it threatens the country, just as world leaders prepared to meet in Seoul for a nuclear summit.
The North's atomic programme is expected to be the subject of discussion at the talks on Monday and Tuesday, which will be attended by US President Barack Obama, Chinese President Hu Jintao and the leaders of Japan and Russia.