Hill made his comments today at a news conference in Seoul after an overnight visit to Pyongyang -- the first by a senior U.S. diplomat to the North Korean capital in nearly five years.
Hill said that during the talks, both the United States and North Korea reaffirmed their commitment to a February accord aimed at North Korea's denuclearization.
"The talks were very detailed, very substantive, and I believe they were also very useful and positive," Hill said.
Hill met with North Korea's foreign minister and top nuclear negotiator in talks on implementing a six-country accord reached in February. The six-country talks are expected to resume in early July.
Under the February deal, North Korea is supposed to end its nuclear weapons program in exchange for aid.
The deal includes the closure of Yongbyon, which U.S. intelligence believes has provided enough plutonium to build at least eight nuclear weapons.
(compiled from agency reports)
A nuclear-capable, short-range missile on display in Islamabad, Pakistan, in March (AFP)
IS PROLIFERATION INEVITABLE? On June 18, RFE/RL hosted a briefing featuring Henry Sokolski, executive director of the Nonproliferation Policy Education Center. Sokolski discussed the challenges to the global nonproliferation regime and what Western countries can do to strengthen it.
LISTENListen to the entire briefing (about 60 minutes):
Real Audio Windows Media