Trucks transport containers at the Qingdao port, in eastern China’s Shandong province, yesterday. China’s Prime Minister Wen Jiabao has warned of a difficult start to the year amid rising concerns over a potential sharp slowdown in the world’s second largest economy. He reiterated pledges to expand domestic demand as authorities try to ward off the effects of crises in the United States and Europe, key markets for China’s export-dependent economy.