TOKYO, Jan. 31 (Xinhua) -- Tokyo stocks opened lower Wednesday tracking Wall Street's overnight decline, with investors in a cautious mood ahead of U.S. President Donald Trump's first State of the Union address.

As of 9:15 a.m., the 225-issue Nikkei Stock Average lost 66.77 points, or 0.29 percent, from Tuesday to 23,225.20.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, dropped 6.69 points, or 0.36 percent, to 1,851.44.

Mining, iron and steel, and insurance-oriented issues comprised notable decliners in the opening minutes of trade.