The United States had led calls for a stable transition of power in North Korea as dead leader Kim Jong Il was shown lying in state by national media.

The pictures of Kim's body wrapped in a shawl and encased in a glass tomb were broadcast as an 11-day period of national mourning began following his death from a heart attack on Saturday.

Placed in the Kumsusan Memorial Palace in Pyongyang, he is shown surrounded by red and white flowers with his head resting on a small white pillow.

Mourners in military uniforms are shown paying their respects, including his son and announced successor Kim Jong Un.

North Korea has announced that Kim's funeral will be held on 28 December, and there were reports that Chinese president Hu Jintao will be the only foreigner in attendance.

Pictures of inconsolable, grieving North Koreans were broadcast on national media on Monday following the news of Kim's death even as some outsiders expressed scepticism that the grief was authentic.

MORE: 18 Strangest 'Facts' Known (Or Invented) About Kim Jong Il

Meanwhile state media in the reclusive, Communist country moved quickly to establish Kim Jong Un as the rightful inheritor of power, labelling him "born of heaven" and describing him as "the eternally immovable mental mainstay of the Korean people".

Fears were raised on the announcement of Kim's death that an unstable or chaotic transition of power could prove dangerous in the highly-militarised, nuclear-armed state.

Tensions were heightened by the announcement that North Korea had fired a test-missile on Monday in an apparent reminder of its military strength, and by the lack of information about new leader Kim Jong Un, who is thought to be just 28 years old.

MORE: Twitter Reacts To Death Of Kim Jong Il

Calls for a stable transition were issued by countries around the world on Monday, including the United States, Japan and Great Britain.

In a statement, US Secretary of State Hillary Clinton said: "We are deeply concerned with the wellbeing of the North Korean people and our thoughts and prayers are with them during these difficult times. It is our hope that the new leadership of the DPRK will choose to guide their nation onto the path of peace by honouring North Korea's commitments, improving relations with its neighbours, and respecting the rights of its people."

"The United States stands ready to help the North Korean people and urges the new leadership to work with the international community to usher in a new era of peace, prosperity and lasting security on the Korean peninsula."

South Korea, with whom its northern neighbour has technically been at war since 1950, also offered its condolences but said that no official delegation would travel to North Korea's capital Pyongyang to pay its respects.

It added that families in South Korea with ties to the North will be allowed to visit, and said it hoped the new leadership would cooperate in the move towards peace.