The US and South Korean military will stage more joint exercises to warn North Korea following its "deliberate" and "inhumane" attack on a South Korean island, their top officers said on Wednesday.
November's deadly bombardment was "a deliberate and illegal armed attack" which violates the UN Charter and the armistice agreement which ended the 1950-53 war, they said in a joint statement after holding talks.
Admiral Mike Mullen, chairman of the US joint chiefs of staff, is visiting Seoul to show solidarity in the wake of the attack which killed two civilians and two marines on Yeonpyeong island and destroyed 29 homes.
He and his counterpart, general Han Min-Koo, said the North's "inhumane actions of killing innocent civilians deserves condemnation".
The military chiefs agreed to strengthen joint efforts to deter further provocation and said they would refine existing plans so they can "resolutely respond to further North Korean aggression".
The two sides said they would continue combined exercises designed to effectively deter North Korean attacks.
Mullen and Han, in their statement read at a press conference, said it was essential to maintain military readiness "in the face of continued reckless behaviour by North Korea".