The 7,600-ton Aegis destroyers were equipped with SPY-1 radar, allowing them to track hundreds of objects simultaneously from up to 1,000 kilometres away, Yonhap News Agency quoted a senior Navy official as saying.
"If the North fires off a missile, we will trace its trajectory," he said.
The vessels would watch both sides of the peninsula, he said. North Korea moved a KN-08 missile to its east coast Thursday, according to several media reports.//DPA