US Defense Secretary Robert Gates arrived in Oman on Sunday for talks with Sultan Qaboos bin Said and was due to visit an aircraft carrier in the Arabian Sea that conducts operations supporting the war in Afghanistan. US Defence Secretary Robert Gates arrived in Oman on Sunday for talks with Sultan Qaboos bin Said and is due to visit an aircraft carrier in the Arabian Sea that conducts operations supporting the war in Afghanistan. Talks were expected to touch on issues including Iraq, Iran, Yemen and Afghanistan, a senior defence official said, adding that the visit was primarily a courtesy call tied to last month's 40th anniversary of the sultan's reign. "This is the highest-level US official to meet with the sultan during a very important and symbolic period," the official said. "The sultan is widely regarded as among the region's most erudite and insightful leaders in terms of regional trends and everything else." Oman maintains good relations with Iran and was instrumental in helping to negotiate the release of one of three US hikers accused by Tehran of straying from Iraq into Iranian territory. Oman has been pressing for the release of the two remaining hikers, who have been held since 2009. The sultan also has pushed for a diplomatic solution to the international dispute over Iran's nuclear programme. "On Iran as you know we have this dual track approach of engagement ... while also holding Iran's feet to the fire with sanctions to keep them honest," the defence official said. "The sultan has been very proactive in pushing for a diplomatic solution and so that's helpful." In what will be a first for the secretary of defence, Gates will fly to the aircraft carrier USS Abraham Lincoln in the Arabian Sea to visit sailors and airmen involved in supporting combat operations in Afghanistan. Asked if the visit to the ship was meant as a signal to Iran, the official said: "It's more just a situation of timing. It's not meant to signal any particular message."