North Korea has a message for the United States: We’re ready to talk. North Korea’s ambassador to the U.N., Sin Son Ho, called CBS News to deliver the message that, though they have defied UN sanctions with missile tests this year, Pyongyang is prepared to negotiate with Washington. “We are not against the dialogue,” he said. “We are not against any negotiations for the issues of common concern.” While the Obama administration has adhered to the format of the six-party talks, North Korea says it will not negotiate in that format. “The six-party talks are gone forever,” Ambassador Sin said, adding that the failure for negotiations so far “is not because of us.” But when asked why North Korea was pursuing its nuclear program, Ambassador Sin gave a chilling reply: "We are always exposed to the nuclear threat of the U.S.," he said, adding, "Japan and South Korea are under the protection of the nuclear umbrella by the United States. And our neighboring countries are all-powerful with nuclear weapons. There is only one country—DPRK—with nuclear vacancy in the region. We are defenseless, so it is our last option—to possess the nuclear deterrent."