The death of North Korea’s long-time leader Kim Jong Il could halt talks aimed at getting the country to give up its nuclear weapons, the West feared last night.

We encourage North Korea to work for peace and security in the region

For his successor, his untested third son Kim Jong Un, is unlikely to risk any step that could be seen as weakness as he seeks to consolidate control.

To prove this, just hours after his 69-year-old father’s death from heart failure due to “great mental and physical strain” the country launched a short-range missile test.

Meanwhile world governments viewed the death of Kim Jong Il with wary optimism.

It is seen as a possibly destabilising moment for the region as power passes to his son but also an opportunity for a new diplomatic start.

British Foreign Secretary William Hague said: “This could be a turning point for North Korea as Kim Jong Un takes over as supreme leader.

“We hope that their new leadership will recognise that engagement with the international community offers the best prospect of improving the lives of ordinary North Korean people.

“We encourage North Korea to work for peace and security in the region and take the steps necessary to allow the resumption of the six-party talks on denuclearisation of the Korean peninsula”.

Secretary of State Hillary Clinton called yesterday for a “peaceful and stable” transition in North Korea and said the US wanted better relations with its people after leader Kim Jong-Il’s death.

“We both share a common interest in a peaceful and stable transition in North Korea as well as ensuring regional peace and stability,” Mrs Clinton said after talks with Japan’s Foreign Minister Koichiro Gemba.

“We reiterate our hope for improved relations with the people of North Korea and remain deeply concerned about their well-being,” she said.

During his 17 years in power, Kim’s pursuit of nuclear weapons and his military’s repeated threats to South Korea and the US have stoked fears that war might again break out or that North Korea might provide weapons of mass destruction to terrorist movements.

South Korea put its military on “high alert” and President Lee Myung-bak convened a national security council meeting.

The Korean peninsula remains technically in a state of war more than 50 years after the Cold War-era armed conflict ended in a cease-fire.

Japanese Prime Minister Yoshihiko Noda held an emergency national security council with top Cabinet members soon after hearing the news.

The announcement of his death jolted financial markets, raising the spectre of more instability on the divided Korean peninsula as the reclusive regime undergoes a leadership succession.

European stock markets fell slightly in early trading. Wall Street was set to open lower.

South Korea’s Kospi index dived nearly 5 per cent but later recouped some losses to close 3.4 per cent lower. Other Asian stock markets also fell.

Australia’s Foreign Minister Kevin Rudd said Kim’s death brings the situation to one of those critical junctures and “an exceptionally difficult period of transition.

“It is critical that everybody exercises appropriate calm and restraint in what is a important development in terms of the overall stability of the region and the security of us all,” he added.

Human rights groups yesterday urged North Korea to change its ways after the death of leader Kim Jong-Il, saying he led a “hell on earth” and killed thousands, if not millions of people.

Human Rights Watch and Amnesty International were both guarded in their hopes for Kim’s son and heir apparent Kim Jong-Un, saying that North Korea has one if not the worst rights records in the world.

“North Korea under Kim Jong-Il has been a human rights hell on earth,” said Kenneth Roth, executive director of Human Rights Watch, estimating Kim was responsible for thousands or even millions of deaths through starvation, prisons, labour camps and public executions.

“Kim Jong-Il will be remembered as the brutal overseer of massive and systematic oppression that included a willingness to let his people starve,” Ms Roth said.

The North Korean leader died of a heart ailment on a train and an autopsy was carried out, a state TV broadcast said.

He is believed to have suffered a stroke in 2008 but he appeared vigorous in photos and videos from recent trips to China and Russia.

Kim Jong 11 is reported to have had a taste for cigars, cognac and gourmet cuisine and was believed to be suffering from diabetes and heart disease.

His body will be placed in the memorial palace in the capital Pyongyang and there will be a 10-day national mourning period. His funeral will be on December 28.

Kim Jong-Il inherited power from his father Kim Il-Sung, the 100th anniversary of whose birth comes next year in another flashpoint date that has US and South Korean analysts watching on nervously.

He presented his own son Jong-Un as the heir apparent in September 2010, extending the communist world’s only dynasty.

Who next?

The young man tipped to be North Korea’s next leader and propel the Kim dynasty into a third generation is even more of an enigma than his father Kim Jong-Il.

North Korean state media yesterday urged people to follow Kim’s youngest son and heir apparent Kim Jong-Un, who is in his late 20s, after announcing that his father had died on Saturday, plunging the country into confusion.

Kim Jong-Un’s life is shrouded in mystery, but in recent years he has been pushed to the forefront as his father apparently speeded up plans for a second dynastic succession after suffering a stroke in August 2008.

In September 2010 his son was made a four-star general and given senior ruling party posts, despite his lack of any military experience. It was only then that state media published his first-ever adult photograph.

Since his elevation, Kim Jong-Un has been constantly at his father’s side, and actively involved in tate affairs.

North Korea’s propaganda machine has rolled into action to build up the same personality cult for Jong-Un that surrounded his father and late grandfather Kim Il-Sung, the founder and “eternal leader” of North Korea who died in 1994.

In recent months, state media began referring to him as “general”, after having previously only used his official title – vice-chairman of the central military commission of the Workers’ Party of Korea.

Little is known for sure about his character but experts believe he has traits in common with his father.

North Korea: Half a century of conflict and hostility

Key dates in the history of a troubled and secretive nation which has been embroiled in rows with its neighbour South Korea and with world powers over its nuclear ambitions.

• 1945: Japan’s colonial rule over Korea ends with its World War II surrender. Korea is divided at the 38th parallel between the North, backed by the Soviet Union, and the South, supported by the US.

• 1950-53: After Soviet and US troops leave the Korean peninsula, the North invades the South and war breaks out. The US intervenes on behalf of the South as part of a United Nations force, and China on the side of the North. The war leaves four million dead. The US retains a major military presence in the South.

• 1988: US imposes sanctions on North Korea after putting it on its list of nations supporting terrorism.

• 1989: US satellite pictures reveal a nuclear reprocessing plant at the Yongbyon complex.

• 1994: The US comes close to war with North Korea over its removal of spent fuel rods from the Yongbyon reactor. Ex-president Jimmy Carter defuses the crisis with a visit to Pyongyang, which vows to freeze and dismantle its nuclear programme in return for energy aid.

• 1998: North Korea fires first long-range ballistic ­missile.

• 2002: US President George W. Bush names North Korea as part of an Axis of Evil. The 1994 accord breaks down after US accusations that the North has a secret nuclear weapons programme.

• 2003: North Korea withdraws from the Nuclear Non-Proliferation Treaty.

• 2005: For the first time, North Korea states that it has nuclear weapons.

• 2006: North Korea carries out its first nuclear test on October 9, sparking international condemnation and more UN sanctions.

• 2007: North Korea agrees to scrap its nuclear facilities in return for economic aid and diplomatic benefits. In July, North Korea closes nuclear site.

• 2008: In June, North Korea blows up the cooling tower at Yongbyon to show its commitment to nuclear disarmament. In October, Washington removes North Korea from its terrorism blacklist.

• 2009
April 5: The North launches a long-range rocket and announces it will quit the six-party talks and restart its Yongbyon complex after UN condemnation.
May 25: North conducts its second nuclear test.

• 2010
March 26: Forty-six sailors die when a South Korean warship sinks near the North Korean border. International investigators later say it was sunk by a North Korean torpedo, an accusation the North denied.
November 12: North Korea unveils uranium enrichment plant to visiting US scientists. Experts say it could be reconfigured to make atomic weapons.

• 2011
July 22: North and South Korean nuclear envoys meet in Bali to discuss possible resumption of six-party talks.
December 19: North Korean state media say Kim Jong-Il died two days previously of a heart attack at the age of 69.