Ryozo Kato, Japan's ambassador to the U.S., expressed concern Tuesday over a bill two senators proposed last week to open up the Japanese and South Korean markets for automobiles and auto parts.

"Of course, the Japanese Embassy will ask the U.S. government (to oppose the bill) and convey its concerns," Kato said at a news conference. "I believe the U.S. government has a similar feeling."

The bill, introduced by Carl Levin, a Democrat from Michigan, and George Voinovich, an Ohio Republican, said the principal negotiating goal of the U.S. in the automotive sector is to increase market access for U.S. vehicles and parts in foreign markets, especially Japan and South Korea.

It would call on the U.S. government to negotiate market-opening agreements with any member country of the Organization for Economic Cooperation and Development where imported cars make up less than 10 percent of the market.