The 24-year-old son, Yoo Gil-hwan, and 21-year-old daughter, Na-on, are feared to have been inside a six-story building when it collapsed in the 6.3-magnitude quake that hit New Zealand's second-largest city last Tuesday. Their father arrived here two days later.

If necessary, the embassy said it plans to bring the siblings' medical records from South Korea to be used by the local police here. It also said it has been impossible to check whether the two were among the 148 people confirmed dead so far, adding that the identification process is likely to take more than a month.

Local rescue authorities said bodies dug up from the rubble were damaged beyond recognition.

Meanwhile, South Korea's foreign ministry said it has decided to send New Zealand the relief supplies it requested, including tents, foldable bottles and electric generators. More than 2,000 items will be sent by air on Tuesday, it said.

The ministry last week withdrew its plan to dispatch South Korean rescue workers after authorities here said there were too many people working at the scene already. The two sides will continue to discuss any further supply of equipment or trained workers to help the ongoing recovery effort, the ministry said.