PARIS (AFP) - France on Saturday voiced concern over escalating tension on the Korean peninsula after Pyongyang said it was in a state of war with Seoul and urged the world's last Stalinist state to refrain from any provocation.

Paris "urges North Korea to refrain from any new provocation and fulfil its international obligations - within the framework of relevant United Nations resolutions - and swiftly return on the path of dialogue," a foreign ministry statement said.

North Korea on Saturday declared it was in a "state of war" with South Korea and warned Seoul and Washington that any provocation would swiftly escalate into an all-out nuclear conflict.

The two Koreas have technically remained at war for the past six decades because the 1950-53 Korean War concluded with an armistice rather than a peace treaty.

The North had announced earlier this month that it was ripping up the armistice and other bilateral peace pacts signed with Seoul in protest against South Korea-US joint military exercises.