(Adds U.S. on Eritrea, paragraphs 2-3) By Evelyn Leopold UNITED NATIONS, Aug 20 (Reuters) - The U.N. Security Council authorized on Monday an African Union force in chaotic Somalia for another six months and asked the secretary-general to develop plans for a possible U.N. troop replacement. In a resolution, approved unanimously, the council also threatened unspecified "measures" against those trying to thwart a peaceful political process, threaten force against the government or the African Union Mission in Somalia (AMISON) or undermine stability in the region. The United States is considering putting Eritrea on its list of state sponsors of terrorism for allegedly funneling weapons to insurgents fighting the Ethiopian-backed government in Somalia. A U.N. monitoring group last month reported that huge quantities of arms, including surface-to-air missiles were provided by Eritrea to Islamic insurgents. Clashes between Islamist insurgents and Ethiopian-backed government troops have intensified in the past two months, despite the convening of a peace congress between Somalia's many clans and factions. Somalia has been a byword for anarchy since the fall of dictator Mohamed Siad Barre in 1991. The council's resolution asked Secretary-General Ban Ki-moon to develop within 30 days "contingency planning for the possible deployment of a U.N. peacekeeping operation" to replace AU troops. This would include sending another assessment mission to the Horn of Africa nation. Few expect the United Nations to field a large force rather than provide financial or technical support to the AU unless fighting dies down and a viable peace process take place. African nations are pressing the United Nations to supply backup for Somalia similar to that initially provided for Sudan's war-torn Darfur region and then field its own force. The AU mission, which should number 8,000, so far consists of only 1,600 Ugandans. Calling the resolution "a very important decision," Congo Republic Ambassador Pascal Gayama, the current council president, said that at a minimum the United Nations should provide "financial, technical and logistical support ... so that African counties would be able to operate." The U.N. envoy to Somalia, Francois Lonseny Fall, told reporters last week that prospects for a U.N. mission continued to depend on political progress in Somalia. But he said the AU expected U.N. troops to replace or absorb its contingents in six months. "The problem that the African Union has is that it doesn't have the resources," South Africa's U.N. Ambassador Dumisani Kumalo said. "The African Union is doing the job that the U.N. is supposed to be doing." "When your house is on fire, the neighbors come with a bucket of water," Kumalo said. "But the neighbors are not the fire engine. The fire engine is the United Nations." The AU's Peace and Security Council last month agreed to extend its force in Somalia for six months and called for the U.N. to deploy peacekeepers.
