The African Union is preparing to intensify its military campaign against Somalia's al-Qaida inspired al-Shabab militants. The United Nations Security Council is being asked to upgrade the size and the firepower of the AU mission in Somalia, AMISOM.

Defense chiefs from five East African countries Wednesday endorsed a plan to boost the authorized strength of the  AMISOM force from 12,000 to 17,700 troops. The African Union Peace and Security is expected to approve the strategy Thursday and send it on to the U.N. Security Council for action next week.

Security Council approval is necessary because the United Nations foots most of the bill for AMISOM.

AU Peace and Security Commissioner Ramtane Lamamra says the plan is designed to capitalize on recent successes, including last Saturday's victory by Ethiopian and Somali Transitional Federal Government forces over al-Shabab rebels at the key town of Beledweyne.

"We have been working on a new strategic concept that will take [into account] the new situation on the ground, the game changers, the forced withdrawal of Shabab from Mogadishu, the new achievements thanks to the initiative by Kenya, TFG in the south, the new also promising initiative taken by Ethiopia in support of TFG with Beledweyne being liberated," Lamamra said.

The United Nations is being asked to provide funds for force enablers that will multiply AMISOM's capability. Lamamra says the strategy also envisions a bigger role for Somali troops, effectively doubling the size of the anti-Shabab forces.

"The new size is based on two assumptions. First, that enablers and force multipliers would be provided to AMISOM, including tactical and transport helicopters. Second assumption, that the Somali security and police force would be empowered. So it means that you will have AMISOM 17,700 and Somali security force, and police, which would represent the equivalent of AMISOM on the ground," Lamamra said.

All of the additional AMISOM manpower will consist of Kenyan troops already on the ground. They will be converted to the AMISOM command.

Despite the key role played by Ethiopian troops in the Beledweyne victory, and the lead role Addis Ababa has played in the overall fight against al-Shabab, Ethiopia has said it will not join AMISOM. Lamamra says Ethiopian commanders have indicated they expect their stay in Somalia to be brief.

"Ethiopia is helping both AMISOM and the TFG to achieve certain strategic results in the region and once that is being done, AMISOM will take over from Ethiopia and and Ethiopia comes back home. There has never been any problem about that," Lamamra said.

The combined force of Kenyan, Ethiopian and AMISOM troops is waging a three-pronged attack against al-Shabab territory in southern Somalia. Kenya is manning a southern front, Ethiopia is moving along a western front, and AMISOM forces are holding a northern front from its base in Mogadishu.

Diplomats who attended Wednesday's meeting of defense chiefs say the proposed upgrade of AMISOM would provide funding for a fourth front along Somalia's eastern coastline. Military strategists have long argued that it would be impossible to defeat al-Shabab without cutting off its supply lines through the rebel-held port of Kismayo.