French President Francois Hollande, on a visit to the Gulf, defended on Tuesday his country's intervention in Mali, saying it had prevented the African country from being overrun by "terrorists".

Speaking to reporters in Dubai, Hollande said his government does not intend to keep forces in Mali, but will remain until security is restored and Islamist fighters eliminated.

Earlier, as he arrived at Peace Camp in Abu Dhabi -- his country's only military base in the region -- Hollande said it will take at least another week before an African force is deployed in Mali.

The French intervention had allowed time for this force to be put together.

"France is at the forefront," said Hollande. "Had it not been there, Mali would have been today entirely occupied by terrorists and other African countries threatened," he said.

Since Friday, French forces have been supporting an offensive by Malian troops against Islamist rebels, who have controlled the north of the vast country since April.

The military intervention has driven Islamists fighters from their strongholds in the north but the rebels Monday pushed farther into the government-held south, into the town of Diabaly, 400 kilometres (250 miles) north of the capital.

Hollande said the French intervention has three objectives -- "ending terrorists attacks," as well as "securing Bamako where we have thousands of citizens and help Mali to restore its territorial integrity."

"France has no intention of staying in Mali," he said.

"But we have an objective, that is when we leave there should be security in Mali, a legitimate authority, an electoral process and no more terrorists threatening" the integrity of the country," he added.

Defence sources told AFP on Tuesday that France's intervention force in the former colony will gradually increase in size to reach 2,500 troops.

As Hollande flew into the oil-rich United Arab Emirates early on Tuesday, his entourage on the presidential plane said some 700 soldiers at the French naval base in Abu Dhabi, along with six Rafale jets stationed there, were on standby to participate in the Mali offensive if needed.

Soon after touching down in Abu Dhabi, Hollande held talks with Mauritanian President Mohamed Ould Abdel Aziz.

Mauritania, Mali's western neighbour, ordered its troops to seal the border to prevent Islamist fighters from escaping into its territory.

Abdel Aziz raised the possibility of his country participating in operation "Serval" if it were asked, according to Hollande's entourage.

The French president said following talks with UAE officials that the oil-rich state backs the intervention and will provide "humanitarian aid, as well as material, financial and possibly military support."

Belgium announced on Tuesday that it will contribute two C-130 transport planes and a medivac helicopter to back up France's offensive.

By a quirk of timing, Hollande's trip to the UAE is also aimed at selling Rafale fighter jets such as those that have been involved in bombing Islamist rebel bases in Mali.

France is keen to make its first foreign sale of the Rafale, which has struggled to find buyers, to support a project that has cost tens of billions of euros.

Plans for Defence Minister Jean-Yves Le Drian to accompany Hollande were scrapped but the high-powered delegation still includes government ministers and leaders of several blue-chip companies.

In Abu Dhabi, Holland also spoke at the opening session of the World Future Energy Summit (WFES), calling for more investment in renewable energy projects to prepare for the post-oil era and to avoid global warming.

"If we don't spend... we will have a catastrophe," Hollande warned.

More than 500 French companies operate in the UAE, which invested nearly four billion euros in France last year.

Also on the agenda were to be energy cooperation, the Syrian crisis and the impasse in the Iranian nuclear standoff, French officials said.

Human Rights Watch has called on Hollande to bring up the issue of human rights in the Gulf country -- both during private talks and publicly.