BEIJING (AP) - China's premier expressed concern about the U.S. dollar and called on Washington on Sunday to take "concrete steps" to reassure Beijing about the safety of its huge Treasury bond holdings.

"Any fluctuation in the value of the U.S. currency is a big concern for us," Premier Wen Jiabao said at a news conference.

"We cannot afford any mistake, how slight it is, when running our financial assets," he said. "I would like the United States to take concrete steps to reassure investors."

China has pressed Washington to control its yawning budget deficit and prevent inflation that would erode the value of the dollar and China's holdings.

The premier said Treasury values were a matter of the "national credibility" of the United States.