By Irwin Arieff UNITED NATIONS, Jan 17 (Reuters) - A second U.N. peacekeeping assessment team heads to Chad and the Central African Republic this weekend after an initial assessment found the area along the border with Sudan's Darfur region too risky for U.N. troops. The team is paying a two-week return visit to the troubled region bordering on Darfur at the request of the U.N. Security Council, U.N. spokesman Farhan Haq said on Wednesday. Its goal is to lay the groundwork for an expected peacekeeping mission there, despite the doubts expressed earlier by the U.N. Department of Peacekeeping Operations. U.N. diplomats say the council demand is straining its relationship with the peacekeeping department and governments that are frequent contributors to U.N. peacekeeping missions but are hesitant to send their troops into an area under fire. A four-year civil war in Darfur spilled over into neighboring Chad and the Central African Republic last year, forcing civilians near the border to flee their homes for camps already crowded with hundreds of thousands of refugees that had earlier fled Darfur. Both countries called for U.N. help, and the Security Council in June asked the peacekeeping department to explore how to protect the camps. But an assessment mission sent in late November recommended against deploying a U.N. mission there until all parties agreed to stop fighting and begin negotiating a political solution. Its report said peacekeepers could be attacked by rebel groups if they tried to stop cross-border activities and that a U.N. force "would be operating in the midst of continuing hostilities and would have no clear exit strategy." But the Security Council insisted on a new assessment after its members complained during a recent closed-door session that the international community was doing too little to protect suffering civilians there, diplomats said. The council reinforced its message with a statement adopted unanimously on Tuesday that called for the reassessment to be conducted immediately and for "updated and finalized" recommendations to be submitted by mid-February. The statement also called for an advance team to be dispatched to the area "as soon as possible" to speed preparations for an expected U.N. mission.