The city of Zushi in Kanagawa Prefecture may file a lawsuit late this month seeking to force the government to end its plan to expand a U.S. military housing complex in an area that extends into both Yokohama and Zushi, municipal officials said Tuesday.

"We have decided to ask for a judicial decision because there is no prospect of a political solution to the issue," Zushi Mayor Kazuyoshi Nagashima said.

Japan and the United States agreed in July 2003 to build an additional 800 housing units in the Yokohama part of the 288-hectare Ikego residential area for the U.S. forces in exchange for the return of four military sites in Yokohama.

Zushi opposes the decision to construct the five or more 20-story buildings, saying the central government broke a 1994 promise not to build additional facilities in the area.