BEIJING (AFP) - China's new president will pay a state visit to Russia and three African countries, the foreign minister said on Saturday, with Beijing looking to step up diplomacy after a protracted leadership transition.

Foreign minister Yang Jiechi said the visit would take place "soon" and that Tanzania, South Africa and the Republic of Congo would comprise the African destinations.

Communist leader Xi Jinping is due to be named state president during China's annual National People's Congress (NPC) parliament session under way in Beijing, which will conclude the country's once-a-decade leadership transition.

Mr Xi took over the ruling party reins in November.

Mr Yang did not provide exact dates for the visit, but the legislature wraps up on March 17 and a summit of BRICS nations - Brazil, Russia, India, China and South Africa - that the president will attend in South Africa starts March 26.

The choice for the new president's first overseas visit appears to combine respect for China's historical ties with Russia, with which it shares a long border, and Beijing's increasingly prominent role in Africa.

"China and Russia are each other's biggest neighbours," Mr Yang told reporters at the NPC, at what was likely to be his last press conference as foreign minister.

"We want to work with the Russian side to seize the opportunity... to inject new and strong impetus to the growth of the comprehensive strategic partnership."

Russia and China stand together on several global diplomatic issues, including the two-year conflict in Syria, where the two permanent UN Security Council members have blocked resolutions that would have introduced sanctions against Bashar al-Assad's regime.

"We don't protect anyone," Mr Yang said of China's position on Syria, re-iterating Beijing's stance that the crisis could only be resolved through "dialogue and negotiations" and not by military means.

He said Syria's people were "bleeding and suffering" and that China was "distressed and concerned".

The visit to Russia also comes at a time of increasing tension on the Korean peninsula, where the UN Security Council just slapped new sanctions on North Korea for its February nuclear test.

China is the North's sole major ally and by far its biggest trading partner, including being its primary energy supplier, but while it backed the UN move Mr Yang said sanctions were not "the fundamental way" to resolve the issue.

Since the UN resolution was passed the North has responded with fresh threats of nuclear war, vowing to scrap peace pacts as its rhetoric reached a frenzied pitch.

The trip to Africa comes with China's resource-hungry economy, the world's second biggest, obtaining many of its raw materials from the continent and Beijing's influence in it growing.

Sino-African trade has ballooned in the last decade and reached US$166.3 billion (S$207 billion) in 2011. China became the continent's largest trading partner in 2009.

Current Chinese President Hu Jintao has overseen a deepening of relations with Africa, visiting three countries in 2004 and hosting a summit of 48 African leaders in Beijing in 2006.

"China and African countries are good brothers, good friends and good partners," said Mr Yang. But China's emergence as a key investor in Africa has also been accompanied by periodic tensions amid complaints by some that Chinese workers are filling the jobs created by the investments.

While in South Africa the new president will attend the March 26-March 27 BRICS summit in Durban, which brings together Brazil, Russia, India, China and South Africa.