The top U.S. diplomat for Africa has met with Somalia's feuding leaders in an attempt to resolve the war-torn nation's political crisis.

U.S. Assistant Secretary of State for African Affairs Jendayi Frazer

Jendayi Frazer held separate meetings with Somali President Abdullahi Yusuf and Prime Minister Nur Hassan Hussein at the airport in Kenya's capital, Nairobi Monday.

There was no immediate word on what was discussed.

President Yusuf attempted to fire the prime minister a little over a week ago. The prime minister rejected the move, and the Somali parliament voted to support Mr. Hussein the next day. However, a group of about 80 lawmakers today declared that the vote was illegal.

The power struggle has heightened concern over Somalia's future once Ethiopian troops who support the government withdraw, a move scheduled for the end of this month.

At a meeting of African Union ministers today, Ethiopia's vice minister of foreign affairs, Fikadu Alemu, turned down an AU request to keep the troops in Somalia a little longer.

On Sunday, a bloc of East African nations condemned President Yusuf's move to fire the prime minister. IGAD (the Inter-Governmental Authority on Development) said it recognizes Mr. Hussein as prime minister and called on nations to impose sanctions against President Yusuf. Kenya has already announced intentions to do so.

The Somali government has been losing territory to Islamist insurgents who impose sharia (Islamic) law in the areas they control.

President Yusuf told al-Jazeera television today that once Ethiopia pulls out, there is nothing to stop insurgent groups like al-Shabab from taking over the entire country.

A small African Union peacekeeping force plans to stay in Mogadishu after the Ethiopians leave. The AU said Sunday that Nigerian troops will join the current force of 3,200 soldiers from Uganda and Burundi.

Fighting between the insurgents and Ethiopian-backed government forces has killed thousands of Somalis over the past two years. More than a million others have been displaced from their homes, causing what aid agencies describe as a humanitarian disaster.