U.S. President Barack Obama met Friday in Saudi Arabia with King Abdullah to address their differences over security interests across the Middle East.
Their meeting outside the Saudi capital, Riyadh, focused mostly on tensions spawned by Syria's civil war and Iran's nuclear program.
The two leaders made no public statements.
The three-year Syrian civil war has contributed to sectarian tensions across the Middle East, and Saudi Arabia has been critical of the U.S. reluctance to provide arms for rebels fighting against Syrian President Bashar al-Assad's government.
Saudi officials also have voiced concern about the tentative dialogue the Obama administration has begun with Iran - the kingdom's top regional rival.
Saudi Arabia holds major reservations about Iran acquiring nuclear capability and the impact it could have on the region.
President Obama and King Abdullah also discussed the situation in Egypt, faltering Israeli-Palestinian peace talks, and efforts to counter violent extremism.
Bilateral differences over Egypt emerged last year when Mr. Obama criticized the ouster of elected Islamist President Mohamed Morsi. The Saudi government provided support for the military-backed government that replaced the ousted president.
Friday's meeting came as King Abdullah made an unprecedented decision to appoint a second heir to the throne. The move appeared aimed at solidifying political stability in the kingdom, which is in a region that has experienced much turmoil in recent years.
The elderly monarch, whose health appears to be frail, appointed a half-brother, Prince Moqren bin Abdul Aziz, as second in line to the throne after Crown Prince Salman. Prince Moqren, a former fighter pilot, is a close ally of King Abdullah.
President Obama's visit to Saudi Arabia marked the last stop on a week-long trip, during which he tried to secure European unity against Russia's military incursion into Crimea and its annexation of the peninsula from Ukraine.