By EURIE HWANG

SEOUL, South Korea - North Korean leader Kim Jong-un limped onto center stage today to commemorate the 20 th anniversary of the death of his grandfather and the nation's founder, Kim Il-sung. State media broadcasted live footage of the mass memorial, packed with thousands of political and military officials applauding their young leader.

The meeting lasted less than 30 minutes and the camera cut away as he left the stage.

It is yet undetermined what caused Kim's limp. He recently took a trip to a naval unit to inspect a prized submarine.

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South Korean media closely inspects Kim's health as his heavy smoking and obesity may lead to health issues.

There are speculations about a scar on Kim's forehead, rumored to be a plastic surgery mark from an operation to make himself look more like his grandfather who is considered the country's "eternal president."

Kim's father, Kim Jung-il, was also shown walking with a limp in August 2008 after suffering what was thought to be a stroke. He died in December 2011, aged 69.

Kim Il-sung supported a large and incurable tennis-ball sized growth on the back of his neck and forbade the state media to film him from certain angles. He also suffered from heart disease before he died at age 82 in 1994.