United Nations nuclear inspectors have been given the go-ahead to return to North Korea to begin the process of shutting down the main nuclear reactor.
The international community has long wanted Yongbyon shut down
The 35-nation board of the UN's nuclear watchdog, the International Atomic Energy Agency (IAEA), approved the mission at a meeting in Vienna.
It will be the first time inspections have been allowed at Yongbyon since UN monitors were expelled in 2002.
Pyongyang has agreed to close the reactor in exchange for energy aid.
The first delivery of aid - a shipment of fuel oil - is expected to arrive from South Korea by the end of the week.
Diplomats in Vienna said the inspection team could be in North Korea within a week to begin the process of verifying the shut-down of Yongbyon, which is capable of producing enough plutonium for a nuclear weapon each year.
The inspectors will install monitoring cameras and seals on equipment at the reactor, as part of a two-year mission that is expected to cost some $5m (£2.48m).
"The shutting down of the facilities, according our experts, should not take much time, probably a few days, but then we will have to install cameras and put other... equipment in place to ensure that we are able to monitor the shutting down of these facilities," said UN nuclear chief Mohamed ElBaradei.
The IAEA meeting was considering the findings of the organisation's deputy director general, Olli Heinonen, and his three-man team, when they visited North Korea last month.
Their report, seen by news agencies, says inspectors have been granted access to all the facilities that are to be shut down, and will be allowed to install all the necessary equipment needed to verify the closure.
North Korea agreed in February that it would shut down the Yongbyon reactor. The agreement was the result of long-running talks with the US, Russia, China, South Korea and Japan.