Finance minister Taro Aso expressed concern Friday over the outlook for the U.S. budget impasse, which has already rattled global financial markets, saying Japan hopes it will be solved as soon as possible.

A protracted U.S. government shutdown "could prompt investors to sell the U.S. dollar and buy the yen," Aso said at a press conference, indicating the government is worried that the yen may again resume an upward climb, impeding recovery in the country's exports.

The U.S. government has suspended various operations since Tuesday, the beginning of fiscal 2014, as the divided Congress has failed to pass a budget for the new fiscal year.

Aso said failure to meet the Oct. 17 deadline for the U.S. Congress to raise the federal government's debt ceiling, which will trigger a default on the debt obligation of the country, will "have greater impact on the world economy" if it really happens.

"We hope that (the United States) will act in an appropriate manner," Aso said.