The US has "learned a great deal" about the role Pakistani scientist AQ Khan played in proliferating nuclear technology, and his network of illegal activities has been dismantled, says Secretary of State Colin Powell.
"(We) are learning a great deal more about the network and we are tracing the network to all of his various customers and all of the different parts of the network infrastructure," he said in response to a question at the State Department.
"I think we have pretty much taken the network apart in the sense that it isn't going to be doing much in the future, and we're going to work hard to pull up everything that we know about it from the past," he added.
The US is committed to working through six-party talks to achieve the complete, verifiable and irreversible dismantlement (CVID) of North Korea's nuclear programmes, Powell said during an interaction with the media following his meeting with South Korean Foreign Minister Ban Ki Moon in Washington on Thursday.