SEOUL, Oct. 1 (Xinhua) -- Former Soviet Union leader Mikhail S.Gorbachev on Wednesday criticized here the United States saying that Washington violated its agreement with Pyongyang and should be responsible for the nuclear deadlock on the Korean Peninsula.

    It's a problem that the Democratic People's Republic of Korea (DPRK) recently backtracked on its pledge, said Gorbachev, who is attending an environmental forum in Seoul, at a press conference.

    He noticed that the United States yet calls the DPRK an axis of evil and has not yet removed it from its list of terrorism-sponsoring nations, saying that "But we also have to look in detail into the fact that the United States violated its agreement" with the DPRK.

    The denuclearization process on the Korean Peninsula was in stalemate as Pyongyang announced to restart the Yongbyon nuclear facilities recently in protest over the U.S. side's delay in removing it from the terrorism-sponsoring nations.

    Christopher Hill, U.S. chief negotiator for the six-party talks on the nuclear issues on the Korean Peninsula, traveled to Pyongyang on Thursday to seek breakthrough into the deadlock.

    Gorbachev said the nuclear issues on the Korean Peninsula should be resolved within the six-party framework, which involves the U.S., the DPRK, China, Russia, South Korea and Japan.

    Gorbachev, 77 also criticized the U.S. and other superpowers for playing negative roles in preventing global warming.

    "The foremost example of disproportionate energy consumption is the United States," he said. "The United States, which has only 2 percent of the world's natural resources and is inhabited by only 5 percent of the world's population, consumes more than 20 percent of natural resources."