North Korea's new leader Kim Jong-un has delivered his first ever televised public speech during a major military parade to mark the centenary of the birth of his grandfather, state TV showed Sunday.

"I offer the purest respect and the greatest honour to great comrades Kim Il-Sung and Kim Jong-Il," he told cheering crowds, referring to his late grandfather and deceased father.

Jong-un, clad in black Mao suit, delivered the speech from the viewing stand looking over tens of thousands of troops taking part in the massive military parade in the capital Pyongyang.

"I express my greetings to our compatriots in South Korea and across the world who dedicate themselves to reunification and the prosperity of the nations," he said in a youthful voice, rarely looking up from his text.

"Let's go on for our final victory!" he said, pointing his finger ahead to cheering troops who repeatedly chanted "Mansei! (long life)" (AFP)