Why has North Korea fired a missile ahead of US-South Korea drills?

North Korea has fired a ballistic missile into waters off its east coast, just days before the United States and South Korea begin annual military drills known as the Ulchi Freedom Shield exercises in the region.The launch at 6am on Wednesday (21:00 GMT) was the second reported North Korean missile test in less than a week amid tensions over Pyongyang’s growing military ties with Russia and concerns about its expanding weapons programme.Recommended Stories list of 3 itemslist 1 of 3Senior Chinese delegation visits North Korea for talkslist 2 of 3Western allies warn North Korean IT workers funding nuclear arsenallist 3 of 3New York Times reveals Trump administration subpoena over North Korea storyend of listNorth Korea has not immediately commented on the latest launch but has repeatedly condemned annual US-South Korea drills in its neighbourhood.Washington and Seoul say the exercises are defensive and designed to prepare their forces for potential North Korean attacks.Here is what you need to know:What has happened?South Korea’s Joint Chiefs of Staff said a ballistic missile was launched from the Wonsan area, where a port city and naval base are located in Kangwon Province, North K...