AMMAN - International powers will search for a peaceful settlement to Syria's civil war with fresh urgency at an Istanbul meeting after a rebel faction aligned itself with al-Qaida, diplomats and opposition sources said on Sunday.Saturday's meeting of 11 countries from the Friends of Syria alliance will come after the al-Nusra Front, among the strongest formations seeking to topple President Bashar Assad, pledged allegiance to al-Qaida leader Ayman al-Zawahri on April 10."We will be meeting under the shadow of the advances of Nusra and other militants. The recent al-Qaida statements have injected a new urgency for the international community to push to end the conflict," said an official who will attend the meeting on the conflict that has killed more than 70,000 people.