The United States has urged Japan to promise during upcoming defense talks that the government will submit to Okinawa Prefecture before the end of the year an environmental assessment report on the Futenma base relocation, diplomatic sources said. Making such a promise will be difficult, because submitting the report would be interpreted as a sign the central government intends to push through the project even though Okinawa is still calling for the air base to be moved outside the prefecture. The government will decide how to deal with Washington''s request during talks between Japan''s Defense Minister Yasuo Ichikawa and US Secretary of Defense Leon Panetta slated for Oct. 25, after Ichikawa visits Okinawa to meet with Gov. Hirokazu Nakaima on Monday, government sources said. The Defense Ministry planned to complete the assessment by the end of 2010, but the process was interrupted when then Japanese Prime Minister Yukio Hatoyama sought to move the base out of Okinawa. Work on the report resumed after top security talks with the US in June, in which both nations'' defense and foreign ministers reaffirmed the deal on the realignment of US forces in Japan, including the relocation of Futenma within Okinawa.