Asked about the country's poor human rights record before his trip, Obama told CNN his administration will continue to apply "steady, consistent pressure."
"They're going to have to change how they do business," he said.
Wearing pants and her head uncovered, Mrs. Obama stood dutifully beside her husband as he shook hands with the Saudi delegation on the airport tarmac this morning and again at Erga Palace on the outskirts of Riyadh.
At times she reached out to shake an occasional hand, but mostly she stood back and offered just a smile.
According to reporters traveling with the president, due to the cultural constraints, the first lady purposely stood slightly behind her husband and waited for a gesture to be made to her by the men in the receiving line. If one of the men initiated a handshake she returned, if not then she simply smiled or nodded politely.