South Africa and France agreed Monday on the need to act "quickly" to prevent an implosion in the deeply troubled Central African Republic at the start of President Francois Hollande's two-day visit.

Host President Jacob Zuma said French Foreign Minister Laurent Fabius, who was in the Central African Republic on Sunday, had told him that the "problem in the country is getting worse."

"We agreed that we need to do something and act quickly."

The South African leader added: "We are going to be ready to be part of the solution to help the Central African Republic come back to its normality."

Hollande, whose trip is seen as part of a campaign to drum up support to resolve the crises plaguing African countries, pledged France's "support (to) regional forces that will be formed under the auspices of the United Nations and the African Union" in the Central African Republic.

The French aim is not "to replace" the African forces "but to guide, assist, support (and) train them," Hollande said.

"This is a new relationship between France and Africa," he said.

France is still heavily involved in security and peacekeeping in its former colonies, where it has often stepped in militarily, and analysts have said it is trying to get South Africa to play a bigger role in continental security efforts.

The Central African Republic is in an "emergency" situation as violence still wracks the nation seven months after a bloody coup, Hollande said.

Early this year, South Africa pulled its troops out of the country after 15 of its soldiers were killed when the Seleka rebel coalition seized power.

Hollande has tried hard to shrug off the negative image of "France-Afrique," a term used to describe the secretive use of political and economic influence between elites in France and its former colonies.

South Africa has in the past criticised France's role in Libya and Ivory Coast.

The two leaders also touched Monday on the unrest in the Democratic Republic of Congo's troubled east, where South Africa is spearheading a UN intervention force.

Meanwhile on the trade front, South Africa clinched $8 billion (nearly six billion euros) in infrastructure deals with France during Hollande's visit, boosting government efforts to tackle a flagging economy and sky-high unemployment.

Africa's largest economy and France signed energy and rail deals and pledged to balance bilateral trade.

An agreement was signed between French energy firm GDF Suez and South Africa for a thermal power plant worth 1.5 billion euros, and also for a solar plant, Hollande told a news conference.

Energy-strapped South Africa has embarked on a multi-billion-dollar building spree to set up new power plants that would double electricity supplies over the next two decades.

A decade of economic growth caught up with the state power giant Eskom in 2008, forcing massive electricity outages that crippled key mining and production industries.

The firm is developing two new giant coal-fired power stations, at least one of which has suffered heavy delays.

Hollande did not give further details on the energy deal in South Africa, which gets 90 percent of its electricity from coal and is exploring nuclear energy as well as shale gas in a bid to reduce this reliance.

"Today marks yet another important milestone in the bilateral relations between South Africa and France," Zuma said. "We have... agreed that we need together to develop trade in a balanced manner."

Hollande's visit is the first by a French leader since Nicolas Sarkozy travelled to Africa's economic powerhouse in 2008 as part of a drive to seek new partnerships beyond France's former colonies.

"France stood by your side during the years of oppression and it will be at your side during the development years ahead," said Hollande.

South Africa received a gloomy warning from the International Monetary Fund this month that it was trailing other emerging market economies and must quickly implement reforms if it wants to avoid a crisis.

The two presidents also finalised a $5.4 billion contract for the overhaul of South Africa's ageing rail fleet by French firm Alstom, which is set to create several thousand jobs.

Under the deal, which was first announced in December last year, Alstom will build 600 trains and 3,600 carriages for South Africa's passenger rail service PRASA over a 10-year period from 2015 to 2025.

About 90 percent of South Africa's current rolling stock is said to date back to the late 1950s.