Beijing (AFP) - A top official will lead China's delegation to North Korea to mark a major anniversary there, state media reported Sunday, amid speculation that ties between the traditional allies are souring.

Liu Yunshan, a member of the Communist Party's politburo standing committee, and other officials will attend the 70th anniversary of the establishment of the North's ruling party, the official Xinhua news agency said.

The seven-member standing committee is led by Xi Jinping, the general secretary of the party and president of the country.

The Chinese delegation was invited by the central committee of the ruling Workers' Party of Korea, the report said, citing the Chinese party's central committee.

Besides attending the anniversary events on October 10 the delegation will make an "official friendly visit" to North Korea, the report added.

China has been North Korea's ally since it sent troops during the 1950-53 Korean War and the two were once said to be "as close as lips and teeth".

Beijing, however, is wary about its neighbour's nuclear programme and has for more than a decade hosted fruitless international talks aimed at persuading Pyongyang to abandon it.

North Korean leader Kim Jong-Un, who came to power after the death of his father Kim Jong-Il in 2011, has yet to even meet Xi.

But the Chinese leader has sat down six times with South Korean President Park Geun-Hye, who took office in 2013.

Last month the North's top newspaper carried congratulatory messages from the leaders of Russia and Cuba on its front page, relegating one from Xi to page two, in what analysts described as a pointed snub.