Tokyo stocks extended losses Wednesday, as investor concerns regrew over a possible escalation of the U.S.-China trade war in the wake of the U.S. Senate's passage of a bill to support pro-democracy protesters in Hong Kong.

The 225-issue Nikkei average fell 144.08 points, or 0.62 percent, to end at 23,148.57. On Tuesday, the key market gauge sank 124.11 points.

The Topix index of all first-section issues of the Tokyo Stock Exchange finished off 5.62 points, or 0.33 percent, at 1,691.11, after sagging 3.99 points the previous day.