U.S. President Barack Obama has called on Yemen's opposition to respond constructively to the initiative of President Ali Abdullah Saleh 'to resolve differences through dialogue and negotiation.' The U.S. embassy in Sanaa on its website said that 'President Obama spoke with Yemeni President Ali Abdullah Saleh last Wednesday and also Secretary of State Hillary Clinton sent a letter to him on Thursday, urging him to continue to work towards a political settlement through dialogue, as well as implement the proposed reforms' President Obama called all parties to continue the national dialogue and return to the negotiating table to reach an agreement that will be welcomed by the Yemeni people.'