Ahead of a rare congress of the ruling party next month, secretive North Korea is revealing details of its weapons development program for the first time, showcasing its push to develop long-range nuclear missiles despite international sanctions.

Until recently, information on the North's weapons program was hard to come by, with foreign governments and experts relying on satellite imagery, tiny samples of atomic particles collected after nuclear tests and mangled parts recovered from long-range launches.

No longer. In just over a month, the North has published articles with detailed color photos on a range of tests and other activities that point to fast-paced efforts to build a nuclear-armed intercontinental ballistic missile (ICBM).