Mali - In an open letter Thursday to U.N. Secretary-General Ban Ki-moon, the president of the African Union urged the U.N. to take immediate military action in northern Mali, which was seized by al-Qaida-linked rebels earlier this year.

Yayi Boni, the president of Benin who is also head of the African Union, said any reticence on the part of the U.N. will be interpreted as a sign of weakness by the terrorists now operating in Mali. The AU is waiting for the U.N. to sign off on a military plan to take back the occupied territory, and the Security Council is expected to discuss it in coming days.

In a report to the Security Council late Wednesday, Ban said the AU plan "needs to be developed further" because fundamental questions on how the force will be led, trained and equipped. Ban acknowledged that with each day, al-Qaida-linked fighters were becoming further entrenched in northern Mali, but he cautioned that a botched military operation could result in human rights abuses.

The sprawling African nation of Mali, once an example of a stable democracy, fell apart in March following a coup by junior officers. In the uncertainty that ensued, rebels including at least three groups with ties to al-Qaida, grabbed control of the nation's distant north. The Islamists now control an area the size of France or Texas, an enormous triangle of land that includes borders with Mauritania, Algeria
and Niger.

Two weeks ago, the African Union asked the U.N. to endorse a military intervention to free northern Mali, calling for 3,300 African soldiers to be deployed for one year. A U.S.-based counterterrorism official who saw the military plan said it was "amateurish" and had "huge, gaping holes." The official insisted on anonymity because he was not authorized to speak on the matter.

Boni, in his letter, said Africa was counting on the U.N. to take decisive action.