(AP) — North Korea says it test-fired a new anti-aircraft missile. It was the fourth weapons launch in recent weeks that experts say is part of a strategy to win sanctions relief and other concessions. South Korea, Japan and the United States typically publicly confirm North Korean ballistic missile launches, but did not do so for Thursday’s. That could indicate the weapon tested may have been a different kind. Seoul’s Joint Chiefs of Staff said Friday that South Korean and U.S. intelligence authorities monitored moves by North Korea but didn’t elaborate. Diplomacy aimed at getting the North to abandon its nuclear arsenal in return for economic and political rewards has largely been deadlocked since early 2019. That has left North Korea under crippling economic sanctions.