US Secretary of State John Kerry arrived Monday in Muscat, Omani state media said, for talks expected to focus on efforts to end Yemen's 19-month conflict.
ONA news agency said Kerry will be in the Gulf sultanate for two days, in one of his last trips as secretary of state before President Barack Obama's administration ends on January 20.
He is scheduled to hold talks on Monday with Oman's Foreign Minister Yusuf bin Alawi and to meet ruler Sultan Qaboos.
Kerry has been pushing for a settlement of Yemen's deadly conflict, which escalated with the military intervention of a Saudi-led coalition to support the government against Iran-backed Huthi rebels in March 2015.
Oman, one of the few Arab states which have good relations with Iran, has used its links to mediate peace talks between the insurgents and Yemen's UN-recognised government of president Abedrabbo Mansour Hadi.
It is also the only Arab nation in the Gulf not part of the Saudi-led coalition, although it maintains good relations with regional powerhouse Saudi Arabia.
More than 7,000 people have been killed and nearly 37,000 wounded in Yemen since March 2015, and the UN says millions are in need of food aid.
Another 21 million people urgently need health services, according to the UN health agency.
After Oman, Kerry will travel to Abu Dhabi for talks on regional conflicts, including Syria.