U.S. Treasury Secretary Paul O'Neill on Thursday urged Japan to act as an engine of the world economy along with the United States and achieve real economic growth of 4 percent to 6 percent a year.

In the Jan. 25 issue of BusinessWeek, O'Neill said, "In the last 10 years or so, the fact that Japan has not been an engine for the world economy has been a passable condition, because we were doing such a great job."

From a world point of view, it is necessary for the U.S. to help Japan achieve real gross domestic product growth of 4 percent to 6 percent, he said.

"There needs to be more than one engine for the world economy," O'Neill said.

It was the first time for O'Neill to comment on Japan's economic condition since being sworn in.

He said Japan is facing a financial asset problem bigger than the savings and loan crisis in the U.S. in the 1980s.

"The Japanese know that," he said. "But not translating it into the financial statements of companies creates a problem of assets being squeezed and squeezed."