An American researcher says North Korea is unlikely to conduct a second nuclear test.

Bruce Klingner told Radio Free Asia Saturday that the North is unlikely to take a risk, though it could conduct another explosion to gain an advantage in negotiations with the United States or to inspire nationalism among its people.

Klingner is with the conservative Heritage Foundation based in Washington.

He warned, however, that stronger sanctions are inevitable if the North conducts a second test.

Another expert on North Korea from the U.S.-based Social Science Research Council said Pyongyang could react to U.S. and Japanese pressure by reprocessing spent fuel rods from its Yongbyon reactor.

Leon Sigal also said stronger U.N. sanctions could lead to a second nuclear test, though the possibility is low.