The king is making his first visit to the White House since ascending the throne in January.
US President Barack Obama is greeting King Salman of Saudi Arabia with assurances that a nuclear deal with Iran also comes with the necessary resources to help check its regional ambitions.
Obama was meeting with Saudi Arabia's King Salman in the Oval Office.
The US has been supporting Saudi airstrikes against the Iran-aided Houthi rebels, who are in a civil war with the US-recognised government.
But the Obama administration also has expressed concerns about civilian casualties there.
The meeting comes as Saudi Arabia seeks assurances from the US that the Iran nuclear deal comes with an effort to check Iran's regional ambitions.