The governor of Japan's southern prefecture of Okinawa has called on the national and US governments to take effective measures to prevent sexual crimes by US military personnel stationed in the prefecture.

Governor Tamaki Denny and members of the prefecture's municipal council, which deals with US military land and base problems, visited the Foreign Ministry in Tokyo on Wednesday. They met State Minister for Foreign Affairs Tsuji Kiyoto.

Their visit comes after a series of unpublicized sexual assault cases surfaced recently involving US military personnel in Okinawa.

Tamaki, who also heads the council, lodged a strong protest and requested that the prefecture be notified without fail about incidents and accidents involving US military personnel. The governor also asked that meetings of a working team involving both countries be resumed to discuss ways to prevent recurrences.

Tsuji noted that US side had earlier announced preventive measures. The state minister said the Japanese and US foreign and defense chiefs confirmed that these measures were being implemented steadily when they had a "two-plus-two" ministerial meeting in Tokyo on Sunday.

Tsuji also explained that the central government will provide prefectural governments with as much information as possible, regardless of whether investigative authorities have made it public. He added that protection of victims' privacy needs to be considered as well.

The Okinawa governor and council members also visited the Defense Ministry and the US Embassy in Japan to make similar requests.