Kenya's PM Raila Odinga is keeping his options open regarding sending troops to Somalia.

Raila Odinga told CNN that, because of Kenya's shared border with Somalia, deployment of troops there has been generally ruled out, even as part of an African Union force. The presence of Kenyan troops could be seen as an invasion, according to prime minister.

But Odinga added that, once other African countries announce their commitments to an expanded AU force force for Somalia, Kenya might review its own position.

Leaders at the recent African Union summit in Uganda called for an expanded AU troop presence in Somalia. They said the Somali crisis had created fertile ground for threats to peace across the region.

Odinga also discussed the threat posed in Kenya by the Somali militant group of Islamist militants, al Shabaab. He said the al Qaida-linked group has already threatened to come to Kenya. Odinga pointed out that they have mounted cross-border raids into his country, one within the past few days that wounded two soldiers. The prime minister said "self-defense" could not be ruled out if these activities continued.

Al-Shabaab claimed responsibility for a suicide attack in Uganda two weeks ago that left 76 people dead. The group said that attack was a response to Uganda's participation in the AU peacekeeping mission in Somalia.