Turkey says no doubt Assad's forces behind poison gas attack ANKARA (Reuters) - Turkish Foreign Minister Ahmet Davutoglu said on Friday intelligence gathered by Ankara left no doubt that the forces of Syrian President Bashar al-Assad were responsible for a poison gas attack near Damascus last week. Turkey has said previously it would be ready to take part in any international action against Assad, even outside the auspices of the United Nations, and has put its armed forces on alert to guard against threats from Syria. "From our point of view, totally based on our national intelligence and assessments by our national experts ... there is no doubt that the regime is responsible," Davutoglu told reporters in the capital Ankara. The United States plans to release an unclassified version of its intelligence assessment of the chemical weapons attack on Friday, a U.S. official said. France said on Friday it still backed action to punish Assad's government for the apparent attack, despite a British parliamentary vote against it, which set back U.S.-led efforts to take military action against Damascus. Russia fiercely opposes any such action, backing the assertions of Damascus that Syrian rebels were behind the chemical attacks. Turkey has long been one of Assad's most vocal critics and has been a staunch supporter of the rebels fighting against him. It has spent around $2 billion sheltering Syrian refugees, according to Prime Minister Tayyip Erdogan. Reporting by Gulsen Solaker; Writing by Daren Butler; Editing by Janet Lawrence