US has not yet assigned blame for Turkey attack: White House

The United States has not yet identified who was behind a car bomb attack in Turkey that killed 28 people, but it has been careful to press Syrian Kurds fighting against Islamic State militants not to target Turkey, the White House said on Thursday.

Deputy national security adviser Ben Rhodes told a news briefing the United States would be talking directly to Ankara about the Wednesday attack, which Turkish Prime Minister Ahmet Davutoglu blamed on a Syrian Kurdish militia fighter.

"We as a government have not settled upon assignment of responsibility," said Rhodes, who strongly condemned the incident. "We've made clear to the Turks that in all of our engagements with the YPG and other Kurdish elements that we make very clear to them the importance of our alliance with Turkey and the importance of them not engaging in efforts that would undermine what should be our focus, which is the shared threat of ISIL," said Rhodes, using an acronym for Islamic State.