KINSHASA, ZAIRE — ZAIRE'S President Mobutu Sese Seko, accusing the West of "wanting my head at any price," rebuffed pressure Sunday to enter into a powersharing deal with opposition leader Etienne Tshisekedi.President Mobutu lashed out at "flagrant interference" by Western governments demanding drastic political reform. "They want my head. They want my head at any price. But I cannot accept this sort of ultimatum. Nobody can dictate policy to me." In Brussels, Belgium said it wanted to join forces with France and the United States to force Mobutu, who took power in a 1965 coup, to compromise with the opposition. France, Belgium, and the US have pressured Mobutu since Army-led looting last month pushed Zaire toward anarchy. But the president said he would not heed calls to reappoint Mr. Tshisekedi, the opposition leader he fired Oct. 21 after only five days as prime minister.