By Yousef Saba, Gram Slattery, Pesha Magid and Federico Maccioni RIYADH (Reuters) - U.S. President Donald Trump signed a strategic economic agreement with Saudi Arabia on Tuesday as the oil power rolled out the red carpet for him at the start of a tour of Gulf states aimed at drumming up trillions of dollars in investments.

The two leaders are expected to discuss US efforts to dismantle Iran's nuclear program, end the war in Gaza, hold down oil prices and more.

RIYADH - U.S. President Donald Trump will arrive in Saudi Arabia on Tuesday morning to kick off a four-day swing through the Gulf region, a trip that will focus more on economic deals than on the security crises besetting the region, from the war in Gaza to the threat of escalation over Iran's nuclear program.