South Korea and the United States have agreed to jointly develop a nuclear energy that cannot be used to produce nuclear weapons.

An official at the Ministry of Science and Technology said on Sunday that the ministry and the U.S. Department of Energy recently signed a revision to an earlier agreement on nuclear energy research for the joint development project.

The official said nuclear energy from conventional light- or heavy-water nuclear reactors can easily be used for developing nuclear weapons, hampering nuclear non-proliferation efforts.

Under the revised agreement, both countries will work to develop a new type of nuclear energy system dubbed "Generation Four," possessing the four strengths of safety, reliability, economical efficiency and non-proliferation.