Images suggest North Korea may be preparing launch of submarine missile -think tank

WASHINGTON, Sept 4 (Reuters) - Satellite imagery of a North Korean shipyard on Friday shows activity suggestive of preparations for a test of a medium-range submarine-launched ballistic missile, a U.S. think tank reported on Friday.

The Center for Strategic and International Studies said the images it published on its website of North Korea's Sinpo shipyard showed several vessels within a secure boat basin, one of which resembled vessels previously used to tow a submersible test stand barge out to sea.

It said the activity was "suggestive, but not conclusive, of preparations for an upcoming test of a Pukguksong-3 submarine launched ballistic missile from the submersible test stand barge."

North Korea said last October it had successfully test-fired a Pukguksong-3, a new submarine-launched ballistic missile (SLBM), from the sea as part of efforts to contain external threats and bolster self-defense.

That launch was seen by analysts as the most provocative by North Korea since it entered dialogue with the United States over its nuclear weapons and missile programs in 2018.

North Korea has suspended long-range missile and nuclear tests since 2017, but efforts led by U.S. President Donald Trump to persuade it to give up its nuclear and missile programs have achieved little.

Trump is seeking reelection in November and a North Korean missile test before that would highlight the lack of progress despite Trump's unprecedented meetings with North Korean leader Kim Jong Un.

South Korea's military said the Pukguksong-3 tested last year flew 450 km (280 miles) and reached an altitude of 910 km (565 miles) and would have had a range of about 1,300 km (800 miles) on a standard trajectory. (Reporting by David Brunnstrom; Editing by Sandra Maler)