PARIS (Reuters) - Militants who killed the U.S. ambassador to Libya in September probably had links to al Qaeda in the Islamic Maghreb (AQIM), the top U.S. general in Africa said on Wednesday, warning that a growing threat from the group must be urgently addressed.
General Carter Ham, head of the United States' Africa Command, said that a military plan unveiled on Sunday by West African regional bloc ECOWAS to dislodge AQIM from northern Mali still needed detailed work, and any intervention would probably take "some months to prepare".
Ham, in Paris to meet French officials to discuss issues including the Mali crisis, expressed concern at mounting al Qaeda influence in the region and beyond.
"If we in the international community don't find a way to address this, the threat will worsen and the network will become stronger and gain capability to export violence," Ham said.
"I don't think today they possess a credible and imminent threat to the U.S. homeland. But that network already killed four Americans," Ham said.
U.S. officials have acknowledged that in the months before the mid-September attack, which killed four Americans including Ambassador Christopher Stevens, there was extensive intelligence about Islamic militants in the Benghazi area.
"There is a growing network of violent extremist organisations and it appears to me very likely that some of the terrorists who participated in the attack in Benghazi have at least some linkages to AQIM," Ham said.
The U.S. congress will hold a hearing on Thursday into the events surrounding the attack.
Once viewed as an example of democratic progress in Africa, Mali was plunged into chaos by a March coup which toppled the president and left a power vacuum that was quickly exploited by rebels to seize the country's vast, desert north.
While former colonial master France, which has several citizens held hostage in the Sahara by al Qaeda-linked groups, is pushing for a swift war, regional powerhouse Algeria prefers a negotiated solution.
The United States, which spent years working with Mali's army, also advocates a more cautious approach. It has said any military intervention should wait until after elections in order to strengthen the political leadership in Bamako.
"Algeria, like the United States and many others believe that negotiation is the start point for this effort," Ham said. "While there may be a military element to this strategy, addressing the political needs of the Tuaregs and other elements in the northern portion of Mali is important."
While European nations plan to send military advisers to train Malian troops, Ham said the United States could not legally do so while the coup leaders were still in power.
He said the United States had not been asked specifically for help by ECOWAS and indicated it would "take months rather than weeks" to rebuild Mali's military capability which had been significantly diminished after the coup.
While 800 to 1,200 hardcore fighters in the north could not be reconciled, a conflict was not inevitable, he said.
Ham said if a political deal with Tuaregs and other groups in the north was reached and confidence in a Bamako government restored then it could turn the local population against AQIM.
Editing by Louise Ireland