U.S. President Barack Obama and Saudi king Abdullah discussed "tactical differences" in their approach to some issues during a meeting in Riyadh on Friday, but agreed both sides remain strategically aligned, a senior U.S. official said. Obama also assured Abdullah that the United States would **t accept a bad nuclear deal with Iran, the official said, adding that Washington remained concerned about providing some shoulder-mounted anti-aircraft ******* to Syrian rebels. In the run-up to his visit to the kingdom, officials had said Obama would aim to persuade the monarch that Saudi concerns that Washington was slowly disengaging from the Middle East and ** longer listening to its old ally were unfounded. Last year senior Saudi officials warned of a "major shift" away from Washington after bitter disagreements about its response to the "Arab Spring" uprisings, and policy towards Iran and Syria, where Riyadh wants more American support for rebels.