Satellite images of a North Korean rocket launch site show evidence of increased preparations for what the West believes is a cover for a long-range missile test.
A mobile radar trailer and rows of what appear to be empty fuel and oxidiser tanks are among the details revealed by the images.
The trailer's dish has an antenna that is thought likely to be a radar tracking system, giving engineers crucial real-time information on the performance of the rocket's engines and guidance system.
The US-Korea Institute at Johns Hopkins School of Advanced International Studies, which made the images public, said they show that Pyongyang "has undertaken more extensive preparations for its planned April rocket launch than previously understood".
North Korea says the launch, scheduled to be held in two weeks, will fire a satellite into orbit to study the country's crops. But Washington believes it is to test missile systems for nuclear weapons that could target the US. APReuse content