NIAMEY France urged African nations on Tuesday to make a concerted effort to tackle a growing Islamist threat in the deserts of southern Libya.
French Foreign Minister Laurent Fabius, speaking on a visit to Niger where suicide bombers attacked a French-run uranium mine last week, said there were signs that Libya's lawless south was becoming a safe haven for Islamist groups in the Sahara.
"It seems we must make a special effort on southern Libya - which is also what Libya wants," Fabius said after meeting Niger President Mahamadou Issoufou. "We spoke about the initiatives which neighboring countries can take in liaison with Libya."
A five-month French-led military campaign broke Islamists' hold over the northern two-thirds of Mali, killing hundreds of al Qaeda-linked fighters and pushing others into neighboring states.
Niger has said the Islamists who carried out Thursday's twin attacks on an Areva (AREVA.PA) mine and a military barracks, which killed 25 people, had crossed the border from Libya. Tripoli has denied this.
Fabius said efforts to address the problem in southern Libya would need support from Tunisia, Algeria, Chad, Mali and Egypt.
"Since, as is often said, a large part of Libya could act as a refuge for terrorist groups, all of these countries must act together," Fabius said, adding that France would assist them with "lots of determination, lots of solidarity".
Libya has become a weapons smuggling route for al Qaeda militants in the Sahara since Muammar Gaddafi's fall in 2011.
Veteran al Qaeda commander Mokhtar Belmokhtar acquired arms there and his fighters used it as a transit route before a mass hostage-taking at a gas plant in Algeria in January, security sources say.
Tripoli is struggling to control armed groups which helped topple Gaddafi and now refuse to lay down their weapons. Parliament in December declared the south a military zone but policing its borders remains a huge task for weak state forces.
Last week's attacks in Niger were claimed jointly by Belmokhtar and the MUJWA militant group which formed part of the Islamist coalition which seized northern Mali last year.
Later on Tuesday, Fabius travelled to Mali where a day earlier the government fixed July 28 as the date for elections, aimed at restoring democracy after a military coup last year and bringing some stability to the conflict-torn country.
Islamist fighters continue to mount sporadic attacks in the north. And several towns, including Kidal, are occupied by the Tuareg separatist group the MNLA, raising doubts that the polls can go forward safely and throughout the country.
The MNLA launched its rebellion in January last year and initially fought alongside al Qaeda-linked forces before being sidelined by the better armed Islamists. Having watered down independence demands, it is calling for talks with the government over securing a degree of autonomy.
"There are discussion happening now. I would like these discussions to wrap up quickly, but in any case it is clear that there cannot be two countries in one country," Fabius said. "So therefore measures will be taken so that Kidal can vote." He did not elaborate.
France is gradually drawing down the 4,000 troops it deployed in Mali but it will keep 1,000 soldiers there after December as a rapid reaction force to tackle any Islamist threat. It will hand routine security operations to a planned 12,000-strong U.N. peacekeeping mission.