By Tabassum Zakaria
WASHINGTON, Aug 27 (Reuters) - The chairman of the U.S. House intelligence committee said on Tuesday that the evidence is "convincing, if not compelling" that the government of Syrian President Bashar al-Assad was behind the chemical weapons attack near Damascus this month.
Representative Mike Rogers, a Republican, said he has looked into the Aug. 21 attack and spoken to U.S. government intelligence analysts and operators, but his committee did not receive a formal consultation from President Barack Obama's administration, despite the seriousness of the issue.
"I believe that evidence exists that is convincing, if not compelling, that the administration of Syria, the government of Syria, was involved in launching those attacks," Rogers told Reuters. "I do not believe that it was a single source person deciding to do it. I believe it came from the (Syrian) administration."
Rogers, whose committee oversees the U.S. intelligence community, said it would be very difficult to determine if Assad had ordered a chemical weapons attack, but such a move would likely involve at least his close associates.
"They have a very tight hold on their military. From what we know, historically, about how their chemical weapons units work, it is a fairly flat line to the office of the president in Syria. So there are not a lot of people that can intercede in that and make it happen," Rogers said.
The "direction has to come from a pretty small group of people connected to the president" for a chemical weapons attack, he said.
Rogers would not comment on any specific pieces of intelligence, nor on what type of chemical weapon is believed to have been used.
The White House said the options being considered to respond to the chemical weapons attack do not include the ouster of Assad. A U.S. intelligence report is expected to be released in coming days.
One of the options that Obama is weighing is cruise missile strikes against Syrian targets, officials have said.
Secretary of State John Kerry, in a forceful statement on Monday about chemical weapons use in Syria, said there was "additional information about this attack" and it was being compiled and reviewed.
Representative Adam Schiff, a Democrat on the House intelligence committee, said the administration may be waiting for more clinical analysis of tissue samples from the scene.
"It's clinical analysis of the tissue samples that have been gathered, it's the evidence that has been obtained by the U.N. team, and by some of the non-governmental organizations that are treating patients there - I think that's a big piece of what the administration is waiting on," Schiff said.
"We have obviously our own intelligence. We have the insights of our regional allies and their intelligence agencies, and a lot in the public domain in terms of these videos. But I think the piece that I haven't seen yet is the clinical piece," he told Reuters.
Rogers said he did not know what additional information Kerry was referring to.
"We do our own independent look, but I have had no formal consultations with the administration on what they are claiming now is new information. I have not had that," Rogers said.
"Informal status updates should not pass as consultation with Congress," he said. "Calling an individual member on an unsecure line - that doesn't count." (Additional reporting by Susan Cornwell; Editing by Stacey Joyce)