North Korea announced Friday its plans to launch a satellite using a long-range rocket, barely two weeks after agreeing to a deal with the U.S. that it wouldn’t do so. The launch, which the country described as both scientific and celebratory, will take place between April 12 and 16 to mark the centenary of the birth of Kim Il-sung, the country’s founder and grandfather of its current leader, Kim Jong-un. However, Seoul has already condemned it as a “grave provocative act against peace and stability on the Korean Peninsula and in Northeast Asia,” and the U.S. State Department has echoed its sentiments. North Korea’s deal with the U.S.—which included halting nuclear tests and long-range missile launches in exchange for U.S. aid—was seen by Washington as a first step to resolving years of tension in the region.