US and North Korean diplomats on Friday resumed discussions aimed at establishing whether the government in Pyongyang intends to return to the six-party nuclear talks deadlocked since 2008. The United States and North Korea have failed to establish diplomatic ties since the end of the Korean War in 1953, in which the US led an international force against China-backed North Korean troops. US State Department spokesman Mark Toner in Washington described the talks as "exploratory" and "businesslike," but also "constructive." The US wants to see whether North Korea is serious about returning to the six-nation talks and making progress and living up to a 2005 nuclear disarmament agreement. The six-party talks to resolve North Korea's nuclear programme involve the United States, Russia, China, Japan and North and South Korea, and have been deadlocked since 2008.