The U.S. assistant secretary of state for East Asia says Washington will hold bilateral talks with North Korea only if Pyongyang guarantees a swift and full resumption of the six-way nuclear dialogue.

At an event held at the U.S. Council on Foreign Relations, Kurt Campbell said patience and caution is of the utmost importance when assessing North Korea's call for a one-on-one meeting with the U.S.

He also cited the North's leader, Kim Jong-il, as telling Chinese Premier Wen Jiabao during their summit earlier this month that Pyongyang is willing to return to the six-way talks but that it needs to first talk with Washington to improve hostile relations.

Campbell said China, which is the host of the six-nation talks as well as the main ally of North Korea, believes Pyongyang should also entertain similar bilateral interactions with the Japanese and South Koreans.