South Korea's state spy agency said it wouldn't rule out the possibility that North Korean leader Kim Jong-un and Chinese President Xi Jinping discussed economic and military cooperation during their recent summit.

According to Bareunmirae Party Rep. Lee Hye-hoon, who chairs the parliamentary intelligence committee, on Tuesday, the National Intelligence Service(NIS) pointed out the fact that minister-level economic and military officials were part of Xi's entourage to Pyongyang last week.

The NIS said the two sides are believed to have discussed Beijing's economic assistance within the framework of international sanctions on Pyongyang.

China is also thought to have suggested strengthening cooperation in all areas through high-ranking exchanges and strategic dialogue.

On the North's denuclearization, the two sides likely agreed to closely coordinate under the current circumstances, while expressing mutual support.

The NIS, meanwhile, said Kim's sister Yo-jong, who is the first vice director of the ruling Workers' Party's propaganda department, is believed to have been promoted into the ranks of the leadership, alongside Choe Ryong-hae, the president of the presidium of the Supreme People's Assembly.

[Photo : YONHAP News]