Obama's shocking case for striking Syria: Gruesome series of videos taken in aftermath of gas attacks that White House is using to persuade Senators and Congressmen to back US air strikes The Obama is showing the new footage to members of Congress to drum up support for his plan for military intervention in Syria Of the 1,429 people killed in the August attack, at least 426 were children In one of the more heartbreaking videos, a room is full of what appear to be the lifeless bodies of dozens of children. In another, men are seen foaming at the mouth and having convulsions President Barack Obama has been showing an officially-verified collection of 13 graphic videos to lawmakers that depict the horrors of the chemical gas attacks in Syria as he lobbies to win approval for his plan to use military force against the regime of President Bashar al-Assad. So far, support for the president's plan has been sparse, with even fellow Democrats opposing the use of military force in Syria. He is preparing a media blitz for Monday and promised Americans in his weekly address on Saturday that 'This would not be another Iraq or Afghanistan.' CNN first obtained the 13 videos showing the carnage of the August 21 chemical weapons attack near the rebel stronghold of Demascus. The Obama administration told lawmakers in the Senate Intelligence Committee - which last week approved plans to attack Syria - that the videos' authenticity has been verified by the intelligence community. Many of the videos shown to senators can be found on Youtube. But what makes this footage unique is the fact that it has been verified by intelligence officials. Horror: The Obama administration is showing videos that show dead children to congressmen to garner support for his plan for military intervention Sarin: the gas used in the August attack causes convulsions, respiratory failure and ultimately death Verified: The videos of children having convulsions and other atrocities have been verified as authentic by intelligence officials The videos show the panic that set in as people began experiencing the effects of chemical nerve agents, specifically sarin gas, which can cause convulsions, respiratory failure and ultimately death. In another, men are seen foaming at the mouth and having convulsions. In all, 1,429 people were killed in the vicious attack, including at least 426 children. The attack allegedly was carried out by the Assad regime, and U.S. lawmakers are now deciding whether a military response is warranted. Obama added in his weekly address: "I know that the American people are weary after a decade of war, even as the war in Iraq has ended, and the war in Afghanistan is winding down. That's why we're not putting our troops in the middle of somebody else's war," Obama said. Attacks: The chemical gas attacks occurred on August 21 in the rebel strongholds near Demascus Tradition: Muslim tradition requires the dead to be wrapped in a religious shroud and buried within 24 hours of death Former U.N. Ambassador Bill Richardson told the network that the footage could be vital in the Obama administration's quest to convince Congress and the general public that military force against Syria is justified. 'That video will sensitize the American people that this isn't just an intervention, that this is a military strike to stop that type of atrocity,' Richardson, a former congressman and former governor of New Mexico, said. Persuasion: Senator Dianne Feinstein is urging all members of Congress to view the video before voting on intervening in Syria Babies: Of the 1,429 people killed in the attack, at least 426 were children Senate Intelligence Committee Chairwoman Dianne Feinstein - who last week voted in favor of military intervention in Syria - has seen the shocking videos and wants all members of Congress to watch them before deciding whether military intervention is justified. President Obama prepared for a national address Tuesday as a growing number of lawmakers, including fellow Democrats, opposed the use of force. The American public didn't yet appear persuaded by Obama's argument that action is needed to deter the future use of chemical weapons. U.S. Secretary of State John Kerry, who met with more than two dozen European foreign ministers on Saturday, insisted that international backing to take strong action against Syrian President Bashar Assad's regime was growing, not receding. Kerry noted that the ministers, who held an informal meeting of the European Union in Vilnius, Lithuania, made powerful statements condemning the attack, and that increasingly there was a sense of conviction that Assad was to blame. Kerry said the U.S. had agreed to provide additional information to those ministers who were not yet convinced that Assad orchestrated the attack. Children lay dying on the floor in a suburb of Demascus after a chemical attack Symptoms: One of the many symtoms of syrin poisoning is foaming at the mouth and convulsions The EU endorsed a 'clear and strong response' to a chemical weapons attack but didn't indicate what type of response they were backing. It also said that evidence strongly points to the Syrian government. Still, the EU urged the U.S. to delay possible military action until U.N. inspectors report their findings. The Europeans were divided on whether military action would be effective. Britain's Parliament has voted against military action. France had been ready to act last week but held off when Obama declared that he would seek the backing of Congress. French President Francois Hollande's announcement appeared to catch French Foreign Minister Laurent Fabius off guard. Earlier on Friday, Fabius told EU foreign ministers that there was no need to wait for the U.N. report because it would simply confirm what was already known - that the chemical weapons attack had occurred - but would not say who was responsible. Hollande indicated Saturday that the U.N. report could be ready in a matter of days, and he would then be prepared to make a decision on a French intervention. 'I said ... that I wanted to wait for the inspectors' report, which I know will be ready within a very reasonable time period, that is, not that far from the decision of the U.S. Congress,' he told French television after meeting with Lebanese President Michel Suleiman in Nice, France. 'So, at that moment, I'll have all the necessary elements that will let me tell the French people the decision I have made for France.' However, Martin Nesirky, chief U.N. spokesman, insisted that there would be no preliminary report. The report on the Aug. 21 attack will be given to the U.N. Security Council and other member states once the lab analysis is complete, Nesirky said. Rescuers try to help a boy through a convulsion after a syrin gas attack in a suburb of Demascus in August 'We are not saying when that will be, except as soon as feasible,' he told The Associated Press. This is a scientific timeline, not a political timeline. Kerry traveled Saturday from Lithuania to Paris to meet with French official and representatives of the Arab League. He joined French Foreign Minister Laurent Fabius in hailing the EU statement. 'Some don't believe in taking military action ever at all,' Kerry said. And some want to wait for one thing or another, but the overwhelming support is moving in the direction of holding the Assad regime accountable. Kerry added: 'This is growing, not receding in terms of the global sense of outrage of what has happened.' Fabius said if no action were taken, there would be little hope for a political solution to the crisis. Obama and other administration officials were preparing a dayslong push to gain public and congressional support for a strike on Syria. The challenges they faced were apparent Saturday. Sen. Mark Pryor, an Arkansas Democrat, said he would oppose military action, and dozens of people picketed outside the White House against Obama's request. Pryor said in a statement that the administration had not met his criteria for gaining his support: a compelling national security interest, a clearly defined mission with a definitive end, and a coalition of allies. Support: President Obama and Secretary Kerry likely will not be able to get Congressional support for intervention in Syria 'Unless there's some new information or some new development or circumstance, I just don't see me changing my vote at this point,' he told The Associated Press in an interview. Protesters at the White House chanted 'They say more war; we say no war' and said their picket line marked a line Congress should not cross as it prepared to vote on the issue. 'Punishment is not at odds with a political solution,' Fabius said. Bashar Assad will not participate in any negotiation as long as he believes himself to be invincible. Saturday's developments left both the U.S. and Europeans in a waiting game. While the Europeans awaited the U.N. inspection report, the Obama administration waited to see if Congress would back a use of force. Meantime, administration officials continued to lobby lawmakers by phone to vote to authorize a limited military strike against the Assad regime. The first Senate vote, expected Wednesday, was likely to be on a resolution authorizing the "limited and specified use" of U.S. armed forces against Syria for no more than 90 days and barring American ground troops from combat. A final vote in the 100-member chamber was expected at week's end. A House vote is likely the week of Sept. Asked about the American public's uneasiness about getting involved in another conflict, Kerry reiterated his view that the use of chemical weapons in the Syrian conflict was a threat to the U.S. 'This case has not yet been made to the American people for more than a few days and we will continue to make the case to the American people,' Kerry said in Paris. 'This concerns ever American's security.'