The U.S. and China are discussing "all kinds of contingencies" in North Korea, the chief U.S. nuclear negotiator Glyn Davies said Tuesday.
Davies was speaking to reporters after a seminar at the Center for Strategic and International Studies in Washington.
It was unprecedented for a senior U.S. official to talk openly about such discussions since China has traditionally been wary of agitating its ally Pyongyang.
Davies was asked about a Kyodo News report that the Chinese military has drawn up a response in internal documents to a potential collapse of the North Korean regime.
Washington and Beijing are discussing the matter because they aim for a joint response, he added.