US seeks 'convincing steps' by North Korea on nuclear issue

The United States is calling for North Korea to take "convincing steps" to prove it is serious about nuclear negotiations, warning words are no longer enough, a top US official said today.

US Secretary of State John Kerry will take the message to South Korea and China during his visit this week, the official said, adding: "the days are long gone when the international community will take North Korea's IOU ... Words alone will not do.