North Korean ambassador to China, Ji Jae-ryong, considered one of the closest aides to the purged uncle of the North's leader, Kim Jong-un, attended a diplomatic event on Wednesday hosted by China's Foreign Minister Wang Yi, a diplomatic source said.

The appearance of Ji at an annual New Year gathering of ambassadors, held at the Diaoyutai state guesthouse, suggests he is conducting business as usual despite the dramatic downfall of Jang Song-thaek, who had long been considered the North's second most powerful official and a guardian of the North's young leader.

"Ambassador Ji attended the New Year reception along with other North Korean diplomats," the source said, speaking on condition of anonymity.

On Tuesday, Ji visited the South African embassy in Beijing and paid tribute to the late Nelson Mandela, according to the source.

The 71-year-old Ji has shared the same political trajectory as Jang over the past three decades and served as a "linking pin" between Jang and the Chinese leadership since he took up the post in 2010.

Jang, who is married to the North's late leader Kim Jong-il's younger sister, Kim Kyong-hui, was removed from all posts and expelled from the ruling Workers' Party at a key party meeting on Sunday for alleged factional actions as well as corruption and womanizing.

North Korea has branded Jang and his followers as anti-party, counter-revolutionary factional figures, an accusation that South Korean officials and experts say could land him in a political prison camp or even result in his execution.

South Korea's spy agency told lawmakers last week that two of Jang's   confidants -- Ri Yong-ha and Jang Su-gil -- had been executed in public.

(Yonhap News)