The United States and South Korea are planning to conduct more joint naval drills this month. After the conclusion of their four days of Yellow Sea manoeuvres today, South Korea's Joint Chiefs of Staff said that the two sides were discussing holding a joint naval exercise this month or in early 2011. He said discussions are still under way on when and where the drill would take place and on what scale.The current war games were intended as a show of force after North Korea launched a deadly attack on a South Korean island last week in which two civilians and two marines were killed.