U.S. nuclear negotiator Christopher Hill says North Korea must understand the price it will pay if it clings to its nuclear ambitions.

In a lecture in New York, which may have been his last as a nuclear envoy, Hill said that if Pyongyang holds on to the 30 kilograms of plutonium it’s currently believed to possess, this will hinder the Korean Peninsula’s chances for a peace treaty and Pyongyang’s access to the global economic system and developmental aid.

He accused North Korea of being 'a momentum killer' when it comes to making progress during the six-way talks. He preached patience and firmness when engaging in talks with the communist country.

Major U.S. media say Hill will soon be off the North Korean nuclear issue and will likely be appointed as ambassador to Iraq.