North Korea has told the United States it has shut down its Yongbyon nuclear facilities, the State Department said on Saturday.
"We welcome this development and look forward to the verification and monitoring of this shutdown by the International Atomic Energy Agency team that has arrived in" North Korea, said spokesman Sean McCormack.
North Korea said last week it would consider suspending the operation of its nuclear facilities as soon as it received the first shipment of oil from South Korea under the February 13 aid-for-disarmament deal.
A South Korean tanker carrying 6,200 metric tons of fuel oil arrived early on Saturday at the port of Sonbong on North Korea's northeastern coast, the Unification Ministry in Seoul said.
McCormack said US negotiators looked forward to the next step of that February 13 agreement, in which North Korea "has committed to declaring all its nuclear programs and disabling all its existing nuclear facilities."