North Korea has a secret missile base near China that could threaten the U.S., a new report says

North Korea has a covert military base near the Chinese border that poses a “potential nuclear threat” to the United States mainland, according to new research. The Sinpung-dong Missile Operating Base is about 17 miles from the border with China in the North Korean province of North Pyongan, researchers from the Center for Strategic and International Studies, a think tank in Washington, said in a report Wednesday.