United States has asked Saudi Arabia to ease its blockade of Yemen. US Secretary of State Rex Tillerson said this just days before the Saudi-led military coalition announced on Wednesday that it would let aid flow through the Yemeni port of Hodeidah and allow UN flights to the capital. <br/><br/>It was not clear if pressure from Washington was the direct cause of the Saudi change of heart but the request from Mr Tillerson to Saudi Arabia's crown prince, Mohammed bin Salman, was one of several US attempts this month to have Riyadh soften its foreign policy.