South Korea, China set for talks on North

Chinese President Xi Jinping has arrived in South Korea for a two-day visit set to focus on North Korea. It is the first time a Chinese leader has visited Seoul before Pyongyang, and comes amid cooler China-North Korea ties. China is traditionally seen as North Korea's biggest trading ally and the nation most able to wield influence over Pyongyang. But Beijing has appeared increasingly frustrated with its neighbour.
Background:
North Korea tops agenda as China's Xi visits Seoul [BBC]
China's Xi visits South Korea as ties strengthen, wary eye on the North [Reuters]