China is to send 700 combat troops to South Sudan in what analysts describe as a significant shift from its stated policy of non-interference in African conflicts.

The first Chinese infantry battalion to take part in a UN peacekeeping mission will be equipped with drones, armoured carriers, antitank missiles, mortars and other weapons, “completely for self-defence purpose”, state media reported.

China is Africa’s biggest trade partner but has taken an arm’s length approach to the continent’s myriad of political and military disputes. But it has been unusually proactive in diplomatic efforts to pacify South Sudan, where it has invested heavily but where civil war has slashed oil production by a third.

Richard Poplak, an author and journalist studying Beijing’s influence on the continent, said: “This does seem to announce a new era in the way China is engaging with Africa. It runs contrary to China’s foreign policy of, ‘We don’t interfere’. It’s an enormous renunciation of that.”

Poplak, who has visited 18 African countries including South Sudan for a forthcoming book, added: “It comes down to interest. The Chinese have poured billions and billions into South Sudan, so many resources that it’s almost baffling. This is a shift in realpolitik: you can’t just talk all the time and not carry a big stick. The Chinese have realised that.”

China is the biggest contributor of peacekeepers among the five permanent members of the UN security council and currently has more than 2,000 posted around the world. But nearly all are engineers, medical and transport workers and security guards.

Poplak said it has previously sent small contingents of elite troops to Mali and South Sudan to guard its personnel but that the new infantry battalion would be of a different order.

However, China would still have far less military presence in Africa than other major powers, at least for the time being, he said. “I don’t think they will be anything as visible or machinelike as France or America but they’ve realised that as well as white hats they need blue hats.

“It’s not possible for anyone here or anyone in Beijing to say where this ends. It’s a precedent and any precedent is a dangerous precedent.”

A rally for the departing Chinese battalion was held on Monday in the city of Laiyang, Shandong province, according to the official Xinhua news agency. An initial contingent of 180 soldiers will fly to South Sudan next month, with the rest of the battalion following in March.

“The 700-strong infantry battalion included 121 officers and 579 soldiers. Forty-three members have participated in peacekeeping missions before. An infantry squad composed of 13 female soldiers will participate in a peacekeeping mission for the first time,” Xinhua reported.

The UN has more than 11,000 peacekeepers in South Sudan, which became independent from Sudan in 2011. Oil accounts for more than 90% of the new country’s foreign revenues.

Fighting broke out in December last year when President Salva Kiir accused his sacked deputy Riek Machar of attempting a coup. The fighting in the capital, Juba, set off a cycle of retaliatory massacres across large swaths of South Sudan, claiming thousands of lives and pushing the country to the brink of famine. Oil-producing regions have endured some of the worst violence.

The state-owned China National Petroleum Corporation (CNPC) said last Sunday it had signed a deal with the government in Juba to increase production. The CNPC said it would use heavy oil recovery technologies in “stabilising and increasing crude output”.

On Monday, Ethiopia’s prime minister, Hailemariam Desalegn, said South Sudan’s leaders could face punitive sanctions from their neighbours as a “last resort” if peace talks fail to end the war. Negotiations in Addis Ababa have led to several ceasefire deals but each has been violated within hours.

A 2011 report by the NGO Saferworld found that, despite its stated neutrality, China is gradually using diplomatic means to push for the resolution of certain conflicts. It also said the Asian power is becoming a major supplier of conventional arms to African states and has increased its contributions to UN peacekeeping missions twentyfold since 2000, with the majority based in Africa.