(CNN) -- U.S. President Barack Obama has pushed the pause button on the path toward U.S. military action in Syria by asking Congress to support his call to strike targets in the Middle Eastern country. But as the U.N. investigates alleged chemical weapons use in Syria and U.S. officials make their case for action, it's still a fast-moving story. Here are the latest developments:
-- At a meeting in Cairo Sunday, Arab League foreign ministers condemned the chemical weapons attack, urged the international community to take action and called for the prosecution of those responsible. "The Syrian regime bears full responsibility for the use of chemical weapons (in) this heinous crime," foreign ministers from the regional organization said in a statement, according to the state-run Saudi Press Agency.
-- Rep. Janice Hahn, D-California, said she took a red-eye flight to attend a classified briefing on Syria in Washington Sunday. "I'm taking this very seriously. ... I wanted to see the facts. We've read classified documents. We've had a classified briefing. And the case is trying to be made that this use of chemical weapons puts our national security at risk and it's worth acting," she told reporters. "I don't know if every member of Congress is there yet. I'm not there yet."
U.S. PREPARES FOR DEBATE
-- Blood and hair samples collected from eastern Damascus have "tested positive for signatures of sarin," U.S. Secretary of State John Kerry said Sunday on CNN's "State of the Union." Kerry said the samples were collected independently of the United Nations investigation into the August 21 suspected chemical weapons attack.
-- Lawmakers won't be back in Washington until September 9. But the Senate Foreign Relations Committee says it'll hold a hearing on Syria this Tuesday.
-- Amid the debate over whether to strike Syria, authorities are tightening up domestic security measures. The FBI and the Department of Homeland Security are warning of a higher risk of cyberattacks after months of similar disruptions by hackers known as the Syrian Electronic Army.
- Rep. Jim Himes, D-Connecticut, said many lawmakers were skeptical at a classified briefing Sunday with White House, State Department and Pentagon officials. "There was a great deal of skepticism in the room about the utility, effectiveness and support that we would have for the kind of strike that the president has proposed. There's not a lot of skepticism, frankly, about whether or not this was an attack carried out by the Syrian regime," he said. "While nobody would say that it's been proven, the vast bulk of the evidence suggests that this was an attack carried out by the Assad regime."
-- Sen. Rand Paul, who has been an outspoken critic of U.S. involvement in Syria, applauded Obama's decision to consult with Congress on the matter. But he said the situation in Syria is simply too murky for American success. "I think the war may escalate out of control and then we have to ask ourselves who is on America's side over there," Paul said on NBC's "Meet The Press." "If the rebels win, will they be America's ally?"
-- Sen. John McCain, who will meet with Obama Monday to discuss the next steps in Syria, told CNN he has questions for the president. "I want to find out whether there is a plan and a strategy. I want to find out whether this is just a pinprick that somehow Bashar Assad can trumpet that he defeated the United States of America," the Arizona Republican said Sunday. "But I will say that if Congress overrules a decision of the president of the United States on an issue of national security, that could set a catastrophic precedent in the future. It would be a very dangerous precedent to be setting."
GLOBAL REACTION TO SYRIA CRISIS
-- Even as Kerry called the evidence "overwhelming" Sunday, the United Nations argued that world leaders should wait until U.N. investigators determine whether chemical weapons were used. "The U.N. mission is uniquely capable of establishing in an impartial and credible manner the facts of any use of chemical weapons," Martin Nesirky, spokesman for Secretary-General Ban Ki-moon, said repeatedly at a news conference.
-- The Arab League called Sunday for the "international community represented by the (United Nations) Security Council to assume its responsibility and take all the deterrent and needed measures against this crime and all crimes of genocide" in Syria, Arab League Secretary General Nabil el-Araby said in a Twitter post, referring to alleged chemical weapons use there last month.
-- Saudi Arabia called for international action in Syria. "The Syrian regime has crossed all the lines with its tyranny. ... It's time for us to ask the international community to carry its responsibility and put an end to this tragedy that is entering its third year," Saudi Foreign Minister Saud al-Faisal said at a meeting of Arab League foreign ministers in Cairo on Sunday. "The Syrian regime has lost its legitimacy within the Arab world and internationally," he said.
-- Egypt opposed foreign intervention in the Syrian crisis. "We have always warned that Syria might be a prey for a foreign intervention that we rejected and continue to reject, regardless of its motives and source," Egyptian Foreign Minister Nabil Fahmy said at the Arab League meeting.
-- Germany's Foreign Minister Guido Westerwelle said the time gained waiting for U.S. congressional approval "must be used to reach a common position of the international community within the U.N. Security Council."
-- France's prime minister will meet with the ministers of foreign affairs and defense, as well as other officials, on Monday to discuss Syria -- two days before an open debate on Wednesday, the government said.
-- "France cannot act alone," Interior Minister Manuel Valls told Europe Radio 1 on Sunday. "There must be a coalition."
-- The opposition Syrian National Coalition said Syrian forces have started transferring ammunition and soldiers from military sites to residential areas as well as schools.
-- An official from the opposition Syrian National Coalition said the group is disappointed by Obama's decision to seek Congress' permission, which will result in further delay in action. "We can't understand how you can promise to help those who are being slaughtered every day in the hundreds, giving them false hope, then change your mind and say let's wait and see," Samir Nashar said.
-- The Local Coordination Committees of Syria, another opposition group, expressed disappointment Sunday that a U.S. strike would be limited. "A limited strike to merely warn Assad today will lead to nothing but his increase in violence, as well as to his complete confidence that no one would prevent him from killing," the group said in a statement. "In the end no one will pay the price but the Syrian people."
-- Maria Saadeh, a member of Syria's parliament, told CNN on Sunday that she sees no justification for a U.S. strike on Syria. "There is no legitimacy to make this attack," she said, accusing rebel groups of using chemical weapons and committing other crimes against humanity.
CNN's Mohammed Jamjoom, Saad Abedine, Yousuf Basil, Josh Levs, Holly Yan, Dana Bash, Tom Dunlavey, Reza Sayah and Catherine E. Shoichet contributed to this report.