North Korea has completed all of the preliminary steps required to conduct a nuclear test, a South Korean government official said. The South detected the closure of the entrance of a tunnel at the Punggye-ri site in a northeastern region of North Korea. It means that Pyongyang is now ready for what could be its fourth nuclear test, the official said. "This is the final step in preparing to test a nuclear device," the official said Thursday. "In theory, there are seven to 14 days to conduct a test once the entrance is sealed." The official added that it was highly likely the North would test an enriched uranium device, as it does not seem to possess a lot of plutonium.
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South Korea official: North Korea ready for nuclear test
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Official: Tunnel closure is last step to ready for test
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Details come as U.S. President Obama visits South Korea
@placeholder announced last month that it wouldn't rule "a new form of a nuclear test" to strengthen its nuclear deterrent capabilities.