U.S. Federal Reserve Board Chairman Alan Greenspan on Wednesday said Japan's economy is showing signs of stabilization thanks to recoveries in the U.S. and Europe.

"Japan is beginning to show signs of stabilization as a consequence of the fact that the U.S. and Europe are beginning to firm," Greenspan said in a testimony before the congressional Joint Economic Committee. "To be sure, there's been a very serious deflationary problem in Japan, but there are the first inklings that that is beginning to stabilize."

The Bank of Japan last week upgraded its economic assessment for the second successive month, saying the pace of deterioration is moderating.

"Japan's economy still continues to deteriorate as a whole, but the pace has moderated somewhat," the Japanese central bank said in its April report on economic and financial developments.