The U.S. bank bailout is inadequate and is contributing to the renewed plunge in global stock markets, Prime Minister Taro Aso said Thursday.

"Since it was insufficient, the market is again falling sharply," Aso told the Upper House Budget Committee, which was wrapping up talks on a supplementary budget.

Aso made his comments as Japan's key stock index plummeted nearly 10 percent in early trading Thursday following another dive on Wall Street amid growing global recession fears.

The U.S. Congress earlier this month approved a plan to use $700 billion in public money to buy bad-mortgage-related securities and loans from troubled financial institutions.

BOJ injects funds

Kyodo News

The Bank of Japan pumped ¥600 billion into the Tokyo money market Thursday in an emergency operation to facilitate interbank borrowing after the overnight plunge in U.S. stocks.

The BOJ decided to pump in fresh liquidity after the Dow Jones industrials' sharp fall Wednesday reignited instability in global financial markets.