Obama vows 'vigorous' probe into Syria chemical arms claims

WASHINGTON - Agence France-Presse / Reuters

President Barack Obama addresses the Planned Parenthood Gala in Washington, April 26. AFP photo

U.S. President Barack Obama on April 26 promised a "vigorous investigation" into reports Syrian forces fired chemical weapons and renewed his warning that proof of their use would be a "game changer."

He told reporters that US authorities had "some evidence that chemical weapons have been used on the population in Syria, these are preliminary assessments, they're based on our intelligence gathering." "We have varying degrees of confidence about the actual use, there's a range of questions about how, when, where these weapons have been used," he said.

The president said that Washington would pursue a "very vigourous investigation and would work with its partners towards a definitive answer on the chemical weapons issues as soon as possible.

He said that as horrific as it was that civilians face mortar fire and other attacks, the use of chemical weapons "crosses another line." "That is going to be a game changer ... we have to make assessments deliberately but I think all of us, not just the United States, but around the world, have to recognize how we cannot stand by and permit the systematic of weapons like chemical weapons on civilian populations.

"This is going to be something that we're going to be paying a lot of attention to, trying to confirm, mobilize the international community around those issues"  on civilian populations," he said during a meeting with Jordan's King Abdullah in the Oval Office.

Earlier, the White House had said it was continuing to study evidence that the Syrian government has used chemical weapons and would not set a timetable for corroborating reports. 

"I'm not going to set a timeline, because the facts need to be what drives this investigation, not a deadline," White House spokesman Jay Carney told reporters at a briefing.

"We are continuing to work to build on the assessments made by the intelligence community, that the degrees of confidence here are varying, that this is not an airtight case," he said.