New Delhi, Sep 16: President Ram Nath Kovind on Saturday condoled the passing away of Marshal of Indian Air Force Arjan Singh, praising him for his contribution in the 1965 war with Pakistan. "Sad at demise of a great air warrior and Marshal of the Air Force Arjan Singh. Condolences to his family and IAF community," tweeted the President, who is also the Supreme Commander of the Armed Forces. "Marshal of the IAF Arjan Singh was a WW II hero and won our nation's gratitude for his military leadership in 1965 war." Arjan Singh, who was on Saturday admitted to Army Hospital (R&R) here after a massive heart attack and in a critical condition, passed away in the evening. He was 98.