By Rebecca Kheel - 01/06/16 10:52 AM EST
The international commission tasked with monitoring nuclear tests cast doubt on North Korea's claim that it tested a hydrogen bomb Tuesday night, saying it appears similar to the one conducted in 2013.
“It is close to what happened in 2013,” Lassina Zerbo, executive secretary of the U.N. Comprehensive Test Ban Treaty Organization, told The Guardian. “I think they are pretty similar in terms of location, magnitude and so forth.”
“This test is a measure for self-defense the DPRK has taken to firmly protect the sovereignty of the country and the vital right of the nation from the ever-growing nuclear threat and blackmail by the U.S.-led hostile forces and to reliably safeguard the peace on the Korean Peninsula and regional security,” North Korea’s statement said.
North Korea’s previous nuclear tests have involved atom bombs; a hydrogen bomb is a much more powerful device. If confirmed to be a hydrogen bomb, the test would mark significant progress in North Korea's nuclear capability.
Zerbo said his agency is working to confirm whether the seismic activity Tuesday night was in fact a nuclear test.
“To confirm if an event is nuclear we need the smoking gun, which is the radio isotopes that are released from a blast,” Zerbo said. “We have a network of stations and the winds will blow the venting to our stations. We have some stations in Japan, in Russia and in the vicinity and those stations may be able to pick up something in the next 48 or 72 hours.”
The commission is not tasked with determining what type of nuclear weapon was tested, but the particles picked up should indicate whether it was hydrogen bomb.
Zerbo also called on the nations that have not ratified the comprehensive test-ban treaty, including the United States, to do so to put pressure on North Korea. The United States, along with Iran, Israel, Egypt and China, signed the treaty but did not ratify it.