President Barack Obama is beginning a visit to Saudi Arabia at a time of strained relations between the US and Gulf countries.
As well as meeting King Salman, he will sit with leaders from Gulf Cooperation Council (GCC) countries.
US Defence Secretary Ashton Carter is on the trip with him.
Mr Carter said they would be seeking help with military and naval operations to counter Iran’s “destabilising activities” in the region.
Later in the week, President Obama will travel to the UK and Germany.