By Khaled Yacoub Oweis AMMAN (Reuters) - The United States sought on Friday to persuade the Syrian opposition to agree to attend international peace talks in Geneva, a day before President Bashar al-Assad's opponents gather to decide on the issue, opposition sources said. U.S. envoy Robert Ford met the senior leadership of the Syrian National Coalition in Istanbul to push them to approve the talks, which aim to end Syria's two-year-old civil war by creating a transitional governing body, coalition members said.