US and South Korean military chiefs Wednesday started talks on ways to deter further attacks by North Korea after its deadly bombardment of a South Korean island.

Admiral Mike Mullen, chairman of the US Joint Chiefs of Staff (JCS), and his counterpart General Han Min-Koo were also expected to discuss the North’s likely motives in shelling the border island, said a spokesman for Seoul’s JCS.

They would talk about ways to improve defence cooperation and are likely to discuss more joint exercises off the Korean peninsula.

The two countries’ navies last week staged their biggest-ever joint exercise as a warning to the North, after its 23rd November attack killed two civilians and two marines, wrecked homes and threw the region into crisis.

This week the South’s military is holding live-fire drills off its coast, ignoring the North’s warnings that it could spark a war.

Mullen, in comments to reporters aboard his plane, said the two sides would review planned exercises and discuss appropriate responses to any future attacks by the North.

The US military chief, quoted by The Wall Street Journal, said future exercises must improve preparedness while not fuelling tensions. “We all need to be mindful of the overall situation as we look at what we would call normal kinds of exercises, or even routine, because normalcy and routine are not what they used to be,” Mullen said.

The South’s military was widely criticised for a perceived weak response to last month’s attack and the defence minister stepped down.

His successor Kim Kwan-Jin, who will meet Mullen later, has vowed next time to use the South’s air power to hit the North’s artillery batteries.

The United States stations some 28,500 troops in the country, and assumes command of both countries’ militaries in case of war. The South currently has an agreement to consult US forces before using its own jet fighters in combat.