Russia said on Tuesday that a treaty it signed with North Korea earlier this year provides for "strategic cooperation" in all areas, but declined to be drawn on how a mutual defence clause in the agreement could be put into practice.

Moscow said Tuesday that a defense pact it signed with North Korea earlier this year is "unambiguous," as tensions flared over Pyongyang's destruction of roads leading to South Korea. North Korea blew up sections of roads and rail lines on its side of the heavily fortified border between the two Koreas on Tuesday,