North Korea is marking the 101st anniversary of the birth of founding father Kim Il-sung.

朝鲜正在举行开国元勋金日成诞辰101周年纪念。

North Korea is celebrating the birthday of Kim Il-sung, left


Leader Kim Jong-un visited the mausoleum（陵墓） of his grandfather and his father Kim Jong-il in Pyongyang, the official KCNA news agency reports.

In recent weeks the North has threatened to attack South Korea, Japan and US bases in the region.

The US has ruled out holding any more "artificial talks" with the North.

"We cannot continue this charade（看手势猜字谜游戏） and we cannot have a policy of rhetoric about denuclearisation. There have to be real steps here," Secretary of State John Kerry told the BBC after talks with leaders in Japan following a tour of East Asia.

Mr Kerry said the North's main diplomatic ally, China, had made a very strong statement criticising Pyongyang for its recent behaviour. He said he hoped Beijing was now recognising the regional instability created by the actions of Kim Jong-un.

Early on Monday Mr Kim was at the Kumsusan mausoleum to pay "high tribute and humblest reverence" to the country's former leaders, KCNA reports.

The streets of Pyongyang are adorned with flags and banners for the holiday, a red-letter day for one of the world's most powerful cults of personality, says the BBC's John Sudworth in Seoul.

It is a reminder perhaps of what really lies behind the recent bellicose threats - a need to ensure the regime's survival, our correspondent adds.

Tensions have been high on the Korean peninsula after North Korea conducted its third underground nuclear test on 12 February that resulted in sanctions from the UN.

There is speculation that the North will use Kim Il-sung's birthday for a missile launch.

At this time last year, it launched a rocket with the stated aim of putting a satellite into orbit to mark the 100th anniversary of Kim Il-sung's birth. The rocket broke up shortly after take-off.

The UN Security Council condemned the launch, which many outside the country saw as an illegal test of long-range missile technology.