Top U.S. nuclear negotiator Christopher Hill says Washington remains firm in its stance that North Korea will not be recognized as a nuclear power.

The envoy made his way to Seoul ahead of U.S. Secretary of State Hillary Clinton's visit to the nation later in the week. He made the remark following talks with South Korea's chief nuclear envoy Kim Sook on Sunday.

The post-meeting interview focused on whether talks between North Korea and the U.S. on the normalization of diplomatic ties could begin before North Korea's complete nuclear dismantlement. In response, Kim said the U.S. stance remains unchanged and that Washington would be willing to engage in normalization discussions should the North agree to completely dismantle its nuclear program.

Hill’s visit to Seoul is his last as chief delegate to the six-way nuclear talks. He said he regrets that he was unable to negotiate a full denuclearization of the North or a full implementation of the September 2005 agreement the U.S. signed with Pyongyang.