RIYADH: U.S. President Barack Obama arrived in Saudi Arabia on Tuesday to pay his respects after the death of King Abdullah, a trip that underscores the importance of a U.S.-Saudi alliance that extends beyond oil interests to regional security.

Deputy National Security Adviser Ben Rhodes told reporters Obama wanted to discuss with the new Saudi King Salman the fight against Islamic State, the volatile situation in Yemen and talks on ending a long running dispute about Iran's nuclear ambitions.

“We do believe that Saudi policy will remain quite similar to how it's been under King Abdullah,” he said, adding Obama wanted to forge the same kind of “close relationship” with Salman as he had with his predecessor.

Obama's visit comes as Washington struggles with worsening strife in the Middle East and counts Saudi Arabia among its few steady partners in a campaign against Islamic State militants who have seized swathes of Iraq and Syria.

The U.S. security headache worsened last week with the resignation of Yemen's government after clashes in the capital involving Iran-backed rebels - a setback to U.S. efforts to contain al Qaeda in that country and to limit the regional influence of Shi'ite Muslim Iran.