Updated 3:20 p.m. ET, 9/1
(CNN) - Blood and hair samples from eastern Damascus, Syria, have "tested positive for signatures of sarin" gas, Secretary of State John Kerry said Sunday, arguing that with "each day that goes by, this case is even stronger."
Kerry said on CNN's "State of the Union" that the U.S. obtained the samples independently from "first responders" and through an "appropriate chain of custody"," not the United Nations chemical weapons inspectors.
"We know that the regime ordered this attack, we know they prepared for it," Kerry said. "We know where the rockets came from. We know where they landed. We know the damage that was done afterwards. We've seen the horrific scenes all over the social media, and we have evidence of it in other ways, and we know that the regime tried to cover up afterwards, so the case is really an overwhelming case."
Fast facts about Sarin gas
On Saturday, President Barack Obama said "well over 1,000 people were murdered" in the August 21 attack. The president proposed what he said would be a limited military action against Syrian President Bashar al-Assad; however, he plans to seek authorization from Congress before taking any further steps.
Obama's recoil on striking Syria draws criticism from both sides
Sarin–a clear, tasteless and odorless nerve agent–is one of the most toxic chemical weapons. Dr. Sanjay Gupta, CNN's chief medical correspondent, said a fraction of an ounce of sarin on a person's skin could be fatal.
"It can be absorbed across the skin, it can be absorbed into the lungs, across the eyes. It's pretty gruesome stuff," he said on CNN's "Piers Morgan Live." "It is so indiscriminate...So you don't even know that you've been exposed, necessarily, until you suddenly start to get sick. And then, it starts pretty quickly and can degrade pretty quickly as well."
Top U.S. officials have said there's no doubt that the Syrian government was behind the attack, while Syrian officials have denied responsibility and blamed jihadists fighting with the rebels.
While British and U.S. intelligence reports say the attack involved chemical weapons, U.N. officials have stressed the importance of waiting for an official report from the U.N. chemical weapons inspectors.
The inspectors left Syria on Saturday, carrying evidence that will determine whether chemical weapons were used in the attack last month. Those results could take up to three weeks.
Could Syria strike back if United States, allies, attack?
In a series of television interviews on Sunday, Kerry defended the president’s decision to seek authorization from Congress before taking military action, saying the move will make the United States “stronger in the end” should the country decide to move forward with a strike.
“It's amazing to me to see people suddenly standing up and taking such affront at the notion that Congress ought to weigh in," he said on CNN. "I mean, I can hear the complaints that would have taken place if the president proceeded unilaterally and people say, ‘Well why didn't you take the time to consult?'”
Addressing concerns that a congressional vote may not take place until next week, Kerry said military action against Syria is not something that needs to happen as soon as possible, like previous situations.
“Since it is not an emergency overnight, as we saw in a place like Libya, where people were about to be slaughtered. Since we have the right to strike at any time if Assad is foolish enough to engage in yet another attack, we believe that it is important before this takes place to have the full investment of the American people and of the Congress,” he told CNN's chief political analyst Gloria Borger.
It's unclear how both chambers of Congress will vote on military action in Syria, as the debate is expected to intensify in the coming days. Congress returns from recess on September 9, but some are calling for lawmakers to come back earlier for a special session so a decision can be made sooner.
Critics have accused the president of being weak and not taking the initiative to launch a strike on his own. Kerry reiterated that Obama has the right to make that call "at any point in time" but added he's "confident" Congress will "do what is right."
"I personally believe at a time when the institutions of governance are being doubted by many people, I think this is a very courageous decision. I think it is a big presidential decision, and no one should misinterpret it, particularly Assad or the opposition," he said.
With the British Parliament voting last week against joining a military invention, Kerry argued the United States still has a "coalition of more than a few" and predicted broader support "as the evidence comes out."
"I think voices will grow over the next days as people see the evidence, and that evidence is becoming more powerful every day," he said.
Asked about the risk of Congress potential voting down authorization, Kerry insisted on "Fox News Sunday" that he doesn't believe that will happen on Capitol Hill.
"I can't contemplate that the Congress would turn its back on all of that responsibility and the fact that we would have in fact granted impunity to a ruthless dictator to continue to gas his people. Those are the stakes," he said. "And I don't believe the Congress will do that."
Liberals supporting WMD propaganda. Gee, where have I heard this before?
Oh yeah, back when the idea of invading Iraq was popular at the moment.
100-to-1 all the roaches that made up the ‘anti-war’ crowd will come back to protest the evil republicans when it becomes unpopular.
I swear to god if we go to another bloody war I will have lost whatever faith I have left in our president and government
If we made Assad listen to John Kerry for an hour, then that would be enough punishment.
We aint takin responsibility for nuttin except spending and raising the debt and finding fault with everyone. – Congressional Perps
We need to take care of our own and not spend all this countries money to fight something that will do no good anyways. These wars have been going on for years and years over there and the U.S. going in is not going to help at all. Just get our people in the military killed. We have kids here homeless our schools are almost broke teachers having to buy supplies help them for a change.
I am amazed at how many villages are missing their idiots any more!!! If chemical weapons are not allowed internationally, then we should uphold that rule. Do you want this to hit the united states soon?? Get ready, its coming if countries allow this no holes barred lets just slaughter people. What is wrong with you people???We have a dam good life here, you want war here? You want to be slaughtered by chemical weapsons you do not even smell nor see coming?? Think again!!
I will contact my Rep and Senators and tell them I don't want any attack on Syria. Let the Arabs fight it out to the end by themselves.
Ah yes, Obama, who stood in front of Roman pillars in Colorado as if he was Julius Caesar: In Germany, as if he was a reincarnation of Pres. Kennedy's "I'm a Berllner " speech....but Obama is/never was even close to being a Caesar or a John Kennedy.....just an "indecider"..
See the blind Americans, always shooting at the world.
Go get the oil boys. But remember you can only push the big boys around so much before they snap back, Be careful
Congress will vote No on this. The American public is clearly against it. Really disappointed in Obama on this that it got this far.
Mission accomplished! Responsibility and blame shifted to Congress by inept "leader" whose overactive mouth got us into this corner.
This is why we have a UN , look how Russia and China look to the world .
They do nothing , similar to congress !
I hope Congress says no. I hope Obama uses that as a reson to stay out of Syria. And I hope it sets a precedent for e next POTUS. If we the people cannot understand why we're bombing someone, then we should not do it. Ever.
This has been going on for about 2 years within Syria, let them work out their own situation alone.
Say "NO" Congressmen and Represenatives !!!!! "NO" will not endanger other countries at this point... Only reconsider this issue if the problem expands beyound Syria...
John Kerry – of blowers of wind, you are one of the blowiest. Please, John, please walk away from the podium. Your words are doing more harm than good.
I am not surprised by the stupidity of people. I give Obama and Kerry credit for doing the right thing. They have been unequivocal in their condemnation of this evil act by the Syrian government. Obama also did the right thing in asking for Congress to decide the matter. The country will be divided on this issue. I think those arguing against intervention have a weak argument. Syria is not Iraq. The closest comparison is Libya and it is rather weak comparison since the situations are quite different.
They sure will...don't get involved...
Tom W, a wimpy, strategically meaningless attack will effectively be the same as doing nothing. We will still be seen as feckless. Also, where does it end? What is the fallout of such an action? At this point, it is more about saving face them anything else. The one thing I have not seen is a long term strategy if he gets us involved, and this is a failing of the administration on many issues, both domestic and foreign.
For once, it will be good to see this Congress do what they're so good at doing: Nothing.
Another blow hard politician.
Congress isn't going to approve an attack.
America is becoming a joke in the eyes of our enemies.
No matter which muslim side we back, we lose and they win by our depletion to war costs in lives & debt, so just stay out. It's their plan to draw the western nations into their wars, no matter which side, in order to have us collapse on our own debts. Like we are doing already. We, the people say 'NO' to more spent on Islam overseas, or here for that matter. Stay home and take care of our own mess – we have plenty on our hands right here.
Party of obstruction and 'NO' – now is really the right time to continue & just say NO!!!
John Kerry is wrong on all accounts!
Everyone needs to let their Congressman how they feel! Not that it will matter to the President!
The prez can't get any backing so decided to punt to congress. Congress should punt it right back and not even have a vote.