It has threatened to strike the Pacific island of Guam, where the US has a military base.

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That would put US bases on Guam within range, although it is not believed that the Musudan has been tested before.

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The US says it is planning to relocate several thousand marines off Okinawa to Guam, but has linked their departure to progress on a new base in the north of the island - which many residents oppose.

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