BEIJING, April 27 -- China on Wednesday welcomed the swearing in of South Sudan's former opposition leader, Riek Machar, as the country's first vice president.

"The swearing in is an important achievement in the South Sudan peace process," Foreign Ministry spokesperson Hua Chunying said at a regular news briefing.

As an important partner of South Sudan, China has constructively engaged in its peace process, firmly supported African countries in solving their problems in an African way and played a major role in helping conflicting parties sign a final peace deal, Hua said.

"China sincerely hopes all parties in South Sudan work to form a transitional government as soon as possible, accelerate reconstruction and realize peace, stability and development," Hua said.

She reiterated China will continue to work with the international community to play a constructive role.

Earlier Tuesday, Machar was sworn in as first vice president shortly after his arrival in Juba, two years after fleeing the city on Dec. 15, 2013.

Civil war erupted in South Sudan in December 2013, when President Salva Kiir accused Machar, his former deputy, of planning a coup, which set off a cycle of retaliatory killings that have split the country along ethnic lines.

The conflict has reopened deep ethnic tensions in the world's youngest country, which only won independence from Sudan in 2011.

Peace talks between Kiir and Machar stalled several times but the two leaders eventually signed a peace agreement in August last year, paving the way for the formation of the Transitional Government of National Unity.