North Korea late last month carried out a test of a liquid propellant rocket engine, a US think tank claimed in its latest report.
Pyongyang conducted an unannounced test during the fourth week of April at the Yunsong vertical engine test stand within the Sohae Satellite Launching Station, Kyodo News Agency reported, citing the Center for Strategic and International Studies.
The Washington-based think tank said that the test shows Pyongyang's plan to advance its development of more sophisticated long-range ballistic missiles, space launch vehicles and satellites.
The imagery from April 29, disclosed by the think tank in its report, showed traces of burned vegetation near the test stand, according to the agency.
Last month, North Korea said that it carried out the first test of its "nuclear trigger" management system, which was overseen by leader Kim Jong Un.
Earlier, Pyongyang also conducted "a power test of a super-large warhead" for a strategic cruise missile and test-fired a new anti-aircraft missile.
