A top U.S. envoy says resolving the nuclear standoff with Pyongyang will be a "slow process." Assistant Secretary of State James Kelly spoke the day after talks with North Korea's staunchest ally, China.
Washington's top diplomat for Asia says he had "very good" talks with Chinese officials, but gave few details.
"So we all agree on the end result, the Korean Peninsula needs to be free of nuclear weapons," he said. " That's something that China, the USA, South Korea, Japan and Russia, really the whole international community, agree on. And it's going to be a slow process to make sure that we achieve this in the right way."
China is North Korea's ally. Washington wants Beijing to push North Korea harder to stop its efforts to build nuclear weapons. China says it is willing to host talks between the United States and North Korea to work out their nuclear dispute.
Foreign Ministry spokeswoman Zhang Qiyue says Mr. Kelly was told China opposes Pyongyang's recent move to abandon the Nuclear Nonproliferation Treaty.
She repeated China's long-held position of supporting dialogue, a peaceful solution, and a nuclear-free Korean Peninsula.
Mr. Kelly's visit is part of a flurry of diplomatic activity aimed at resolving the nuclear standoff with North Korea.
Chinese officials say a high-level Russian envoy will confer this week with Beijing officials on the North Korean issue before heading to Pyongyang for talks.
Russia's top Asia expert, Alexander Losyukov, heads the delegation. He follows visits to Pyongyang this week by a high-level delegation from Australia and a special envoy from the United Nations.
On Wednesday, North Korea rebuffed U.S. offers to provide aid once concerns about its nuclear ambitions are cleared up.
The dispute erupted in October when Washington said North Korea broke international agreements with a secret program to build nuclear weapons. North Korea denies admitting it is building nuclear weapons.