According to the agency, the test was overseen by the country's leader, Kim Jong-un.
The tests confirmed all tactical and technological specifications of the system, it added.
On Saturday morning, Pyongyang had launched unidentified projectiles into the Sea of Japan from the eastern province of South Hamgyong. The projectiles, which are thought to be short-range ballistic missiles, flew 380 kilometres (236 miles) at a maximum altitude of 97 kilometres, according to the South Korean Joint Chiefs of Staff. The launches were the first after the completion of the US-South Korean exercises, which took place from August 5 to August 20 and caused a sharply negative reaction in Pyongyang. US President Donald Trump earlier said that Kim Jong Un had promised to stop the launches when the US and South Korean exercises are over.