The situation in Darfur is unacceptable, British Prime Minister Tony Blair said Saturday, and he urged international pressure on the Sudanese government and rebels to stop fighting immediately. He said the African Union force in Sudan deserved thanks for its efforts, and noted that the UN Security Council has authorized a UN peacekeeping force to take over. "I do not understand the government of Sudan's rejection of the UN force, or its threat to withdraw its welcome from the (African Union). This does not match the commitment to peace the government showed in May by signing" the peace agreement, Blair said. The British premier said the coming weeks were "crucial." "Sudan will stay at the top of my agenda," he added.