Alexander Losyukov said Russia was not surprised that Pyongyang will be unable to scrap all its nuclear facilities by the end of the year, as previously agreed.
"The decommissioning of nuclear installations is a very complex technical process, and specialists give different assessments on that score," he told a news conference at RIA Novosti.
He said it could take several months if not a year to complete the process.
Under a deal made with China, the United States, South Korea, Russia and Japan, North Korea is to decommission all of its nuclear facilities in Yongbyon and submit a complete list of its nuclear programs by the end of the year.
North Korea's Central Telegraph Agency circulated a statement in early December confirming Pyongyang's commitments and urging the other negotiating parties to fulfill their promises on political and economic concessions, such as striking the Communist state off the U.S. list of countries supporting terrorism and delivering 950,000 tons of fuel oil for North Korean thermal power plants.
North Korea has already received a total of 100,000 tons of heavy fuel oil from South Korea and China for shutting down five nuclear facilities earlier in the year under a February 13 aid-for-denuclearization deal, a major breakthrough in the talks.
