China on Wednesday expressed serious concern and called for calm from all sides after North Korea test-fired a barrage of missiles.

"We are seriously concerned about the events that have occured," Foreign Ministry spokesman Liu Jianchao said in a statement posted on the ministry Web site (www.fmprc.gov.cn)

"We hope that all sides will maintain calm and restraint, and do things conducive to the peace and stability of the Korean peninsula and Northeast Asia and do not take any further steps that will add to tensions and further complicate the situation."

North Korea launched at least six missiles on Wednesday, including a long-range Taepodong-2, a move US President George W. Bush said defied the international community.

China had urged a peaceful solution and restraint from all sides in the run up to the launch.

Beijing has been eager to revive six-party talks aimed at dismantling North Korea's nuclear programmes, and was sending Vice Premier Hui Liangyu to North Korea on Monday to mark the 45th anniversary of a Sino-North Korean friendship treaty.