US Secretary of State John Kerry has met Saudi King Salman ahead of a week of crunch talks on the conflicts in Syria and Libya.
Riyadh have been a key supporter of rebels fighting to overthrow the Damascus regime of President Bashar al-Assad.
Its allies Cairo and Abu Dhabi have also been major supporters of the administration in eastern Libya which is still withholding its support from a UN- and US-backed unity government in Tripoli.
Official said Saudi in talks with his Saudi counterpart Adel al-Jubeir, Kerry discussed “regional issues… mainly developments in Syria,”.
“I want to thank you for the many things that Saudi Arabia is working on with us to great effect,” he said.
Mr Kerry is to fly to Vienna later on Sunday for the meetings on Libya and Syria on Monday and Tuesday.
On Wednesday, he will fly on to Brussels for a NATO foreign ministers’ meeting and talks on the full range of challenges facing the Western allies.
Kerry’s spokesman John Kirby said the secretary of state and Italian Foreign Minister Paolo Gentiloni would jointly host the Libya conflict meeting.
Participants would “discuss international support for the new Government of National Accord, with a focus on security,” Kirby said.
Officials said the fledgling regime is drawing up a list of requests for Western partners to assist its forces with arms, training and intelligence.
After the Libya meeting, Kerry and Russian Foreign Minister Sergei Lavrov would lead a meeting of the 17-nation International Syria Support Group.
Kirby said the goal was to “ensure humanitarian access throughout the country, and to expedite a negotiated political transition in Syria.”
Officials hope that next week’s meeting would inject new life into the peace process and if the ceasefire holds, it would also secure talks on forming a unity government.