Anchored by Jake Tapper, The Lead airs at 4 p.m. ET on CNN.
Continuing coverage of Malaysia Airlines Flight 17. Plus, the latest on Mideast tensions.
The United States has evidence that chemical weapons have been used in Syria, Defense Secretary Chuck Hagel said Thursday.
"The U.S. intelligence community assesses with some degree of varying confidence that the Syrian regime has used chemical weapons on a small scale in Syria, specifically the chemical agent sarin," Hagel said.
When asked if the intelligence crosses the "red line" President Obama said in the past could trigger a U.S. military response in Syria, Hagel said it is too soon to say.
A White House official told reporters on background that because the Obama administration takes the red line so seriously, they need to gather more evidence to make a determination that the Assad regime crossed it before they can decide their next move. The official also said they are keeping Congress in the loop on developments in Syria.
Sen. John McCain, R-Arizona, said he is disappointed, but not surprised that the administration needs to gather more evidence.
"The president has not wanted to engage in Syria in any way, any meaningful for a couple years, while 70,000 to 80,000 people have been slaughtered," said McCain.
We need to give Syrian rebels "a safe zone, we need to supply them with weapons going to the right people, and we need to be prepared to secure these caches of chemical weapons in the event that [Syrian leader Bashar al Assad] uses them," said McCain.
Lessons learned from former President George W. Bush's administration's erroneous intelligence of weapons of mass destruction in Iraq, White House officials suggest, are informing the Obama administration's decision to be more cautious. It may indeed be prudent to absolutely confirm the use of chemical weapons, since the intelligence does vary.
"Why should, frankly, chemical weapons be a red line, when he's slaughtering, and massacring, and mass raping, and torturing his own people?" said McCain.
Not engaging in Syria, said McCain, has "been one of the most shameful chapters in American history."