President Moon Jae-in has expressed his condolences to the victims and the bereaved families of this week's fatal Marine helicopter crash. 

Presidential Spokesman Kim Eui-kyeom said the president extended his heartfelt sympathy during a meeting on Thursday with new Naval Chief of Naval Operations Sim Seung-seob at the top office. 

Moon asked Sim to attentively handle the case so the victims and their families receive due respect and compensation for their sacrifices.  

The president said the most important thing is to properly and swiftly determine the cause of the crash, urging the military to come up with fundamental measures to prevent something similar happening again in the future. 

The MUH-1 helicopter crashed on Tuesday after taking off for a test run within a military unit in Pohang, North Gyeongsang Province, killing five Marines and injuring the other onboard.