Prime Minister Naoto Kan on Friday defended his remarks on the downgrade of Japan's sovereign credit rating by Standard & Poor's, saying he had yet to be informed of the news when he said he was "not familiar with the matter."

Kan's remark Thursday drew criticism from opposition lawmakers and market analysts, who said it appeared as if the prime minister was ignorant of the meaning and possible impact of the S&P downgrade, which lowered Japan's rating to AA- from AA, the first cut in nine years.

Later in the day, Kan said it was "good" that the latest downgrade of Japan's sovereign debt rating by Standard & Poor's has not had a big influence on financial markets.