A senior presidential aide says North Korea must apologize for sinking the “Cheonan” naval vessel if it wants large-scale humanitarian aid from South Korea.

The presidential secretary for national security strategy, Kim Tae-hyo, said Wednesday that the May 24th ban placed on dealings with North Korea in response to the sinking of the Cheonan are still in effect.

The aide also said that inter-Korean economic cooperation hinges on whether the North can acknowledge its role in the sinking of the vessel.

Kim added that President Lee Myung-bak’s recent remark about the appropriate management of inter-Korean relations means that South Korea could change its stance and move forward in terms of inter-Korean relations if Pyongyang acts responsibly.

Kim also said that North’s commitment to denuclearization is key to resuming the six-party talks.