BEIJING - Delegates from China were absent from North Korea's once-in-a-generation party congress, Chinese media said Friday, in a potential sign of fraying ties between Pyongyang and its most important ally.
Beijing is a key supporter of the hermit kingdom, providing an economic lifeline that has allowed it to ride out waves of international sanctions.
But China's representatives were not invited to the gathering of North Korea's top political leaders, according to the Global Times, a newspaper with close ties to the Chinese Communist Party.
"North Korea wants to maintain its independent stance," Zheng Jiyong, director of the Centre for Korean Studies at Fudan University told the newspaper.
"It can't decide who to invite because it involves the interests of many sides." Details about the secretive party congress have been scant, and it is not clear if any foreign delegates were invited to attend.
The relationship between the two nations, once said to be as close as lips and teeth, has become increasingly strained since the death of North Korea leader Kim Jong-Il.
His son, Kim Jong-Un, has yet to visit China and frequently thumbs his nose at his ally, despite Pyongyang's reliance on Chinese trade.
A recent string of nuclear and ballistic missile tests have tried Beijing's patience.
But it has been reluctant to take measures against North Korea, fearing that they could destabilise the regime, creating a refugee crisis and swinging the regional balance of power towards the United States.
A large Chinese delegation attended the last Workers' Party congress in 1980, headed by Li Xiannian, later China's official head of state.
Beijing's foreign ministry spokesman Hong Lei declined to confirm that no Chinese officials were attending this time.
But he said that China hopes North Korea can "achieve national development" and "heed the calls of the international community and work with us to maintain the peace and stability of northeast Asia".
Kim may want to use the congress to adjust the balance of power between the military and the party, Zheng told the Global Times, adding: "Kim may want to replace old cadres with younger ones who are able to better execute his orders." In an editorial, the paper said that China's relationship with the country was complicated.
Beijing is "resolutely opposing Pyongyang's nuclear development", it said.
"Many forces are now cursing the country, but China will never be one of them."