A newspaper published by China's ruling Communist Party on Tuesday said there are "differences" between Beijing and Pyongyang over North Korea's nuclear ambitions, but their friendly relations are in the interests of the old allies.

The editorial by the Global Times newspaper appeared to underscore how it is difficult for China to rein in North Korea's nuclear weapons program. At the same time, it indicated a desire to avoid acrimony with the unpredictable regime led by Kim Jong-un.

China has sidestepped a question on whether Chinese President Xi Jinping held a one-on-one meeting with a senior North Korean official who attended last week's military parade marking the end of World War II.

Choe Ryong-hae, secretary of the Central Committee of North Korea's ruling Workers' Party, attended the Chinese military parade Thursday, along with about 30 heads of state, including South Korean President Park Geun-hye and Russian President Vladimir Putin. Park held a high-profile summit with Xi ahead of the military parade.

The Chinese newspaper said North Korea's choice of Choe to attend the military parade came as no surprise.

"At present, the China-North Korea relations are more subtle and delicate, but this should stay controllable," the editorial read.

"On the one hand, leaders of China and North Korea have not met. It is an obvious fact," it said, but "friendly relations" between North Korea and China would make them look for "the right opportunity."

"Differences over the nuclear issue have not been avoided, but the understanding of importance of 'China-North Korea friendly relations is not shakeable," it said.

North Korea is China's only treaty ally, but their political ties remain strained over the North's nuclear ambitions.

Kim, the North's young leader, has yet to visit China since taking power in late 2011, following the death of his father, Kim Jong-il.

Despite strained political ties, China is North Korea's economic lifeline and diplomatic backer at the United Nations.

South Korea and the U.S. have called for China to exert more pressure to persuade North Korea to abandon its nuclear program, but Beijing's stance over its ideological ally, Pyongyang, has often been self-contradictory.

Many analysts believe that the Chinese Communist Party leadership won't put enough pressure on North Korea to give up its nuclear ambitions because a sudden collapse of the North's regime could threaten China's own security interests. (Yonhap)