TOKYO (AFP) - US Defense Secretary Robert Gates on Tuesday rejected demands by Japans new government to review a deal between the two allies on the future of a controversial major US airbase. Gates made the comments on his plane en route to Tokyo, before he arrived as the first top US official to visit Japan since the new centre-left government took power here just over a month ago. New premier Yukio Hatoyama pledged during campaigning to look again at the 2006 agreement struck by his conservative predecessor and the former US administration of George W. Bush. That agreement calls for relocating by 2014 the US airbase from an urban part in the south of Okinawa to a coastal area on the north of the island, and transferring 8,000 Marines off Okinawa to Guam. But Gates ruled out major revisions to the deal after Hatoyama earlier suggested the base may be moved entirely off the island. We think we need to progress with the agreement that was negotiated, Gates said hours before he met Japans FM Katsuya Okada. Gates said that although the Obama administration understood the new governments desire to review certain policies, the agreement had been years in the making and other options had already been exhausted. Weve looked at, over the years, all these alternatives and they are either politically untenable or operationally unworkable, he said. The US military presence on Okinawa has long angered residents because of aircraft noise and the risk of accidents, while crimes committed by US service personnel have caused friction with the local community. Gates two-day visit is the first by a member of President Barack Obamas cabinet since Japans new government took power to end decades of conservative rule and vowing less subservient ties with the United States. After shaking hands with the American defence secretary, Okada said his government recognised the importance of US-Japan relations and that their alliance faced some specific challenges. We would like to solve the challenges in a positive manner, he said. Gates said as the new Japanese government assumed its responsibilities, the United States stands with you. And he suggested in diplomatic language that Washington expected the new leadership to uphold agreements worked out under previous governments. We are committed to advancing and implementing our agreed alliance transformation agenda, he said. Hatoyamas government, which in opposition criticised Japan abetting American wars, has also announced it would end in January an Indian Ocean naval refuelling mission in support of the Afghanistan war effort. Washington is anxious to secure assurances from the new government before Obamas scheduled visit to Japan on November 12-13. Gates was due to visit Seoul on Wednesday and Thursday before heading to Slovakia for a NATO meeting of defense ministers on Friday. He said earlier he expected to discuss in Japan and South Korea economic and other possible assistance in support of the NATO-led mission in Afghanistan. Hatoyamas government has said it is considering new civilian aid as a substitute for the naval mission it plans to end. Defence Minister Toshimi Kitazawa said Tuesday he would also study sending military personnel to help aid efforts in war-torn Afghanistan. If you look at the opinions of the international community, including Europe, I have come to worry whether civilian help alone is sufficient as an alternative, said Kitazawa, who was due to meet Gates on Wednesday. In what way can the Self Defense Forces participate in the efforts? The government has not been able to engage in substantial debate, but I personally wish to study the matter by soliciting ideas from many people. Japans armed forces are barred under the countrys pacifist post-war constitution from offensive combat operations, but they have taken part in overseas humanitarian and military support missions.