Toyota Motor Corp., the biggest exporter of autos to the U.S., is trying to cut production costs for Yaris and Corolla cars as the rising yen makes it unprofitable to build economy cars in Japan for sale abroad.

"Given the current exchange-rate situation, it isn't feasible, in terms of a business model, for us to produce Corolla or Yaris in Japan and export them," Atsushi Niimi, executive vice president for global manufacturing, said in an interview in San Antonio on Friday. "We're working very hard to reduce costs to maintain the appeal of these cars."

Toyota and its domestic competitors are scrambling to combat the surging yen, which is up at least 3 percent against each of the world's 16 major currencies this year. The currency is up more than 7 percent against the dollar and more than 14 percent against the euro.