"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.
"The council also called for providing the required forms of support for the Syrian people to defend themselves and the need for concerted Arab and international efforts to help them," the statement said.
Arab League Secretary General Nabil el-Araby said in a Twitter post that the league was calling for 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.
But the statements Sunday did not directly refer to the United States, and it's unclear how much international support the U.S. government would have if it chooses to strike Syria.
At the Arab League meeting, Saudi Arabia called for international action, but Egypt said it was opposed to foreign intervention in the Syrian crisis.
Britain has voted against taking any military action in Syria, and France said it won't act without the United States as a partner.
German Foreign Minister Guido Westerwelle tweeted Sunday that 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."
Amid the debate over whether to strike Syria, U.S. authorities are tightening domestic security measures. The FBI and the Department of Homeland Security are warning of a higher risk of cyberattacks after months of disruptions by hackers known as the Syrian Electronic Army, and authorities say more attacks are likely.
Opposition: Obama gave false hope
The shift to ask for approval from Congress left some analysts scratching their heads.
"The decision-making has been so confused and muddled that it's difficult to put the word 'wise' in front of anything they're doing right now," CNN's Fareed Zakaria said on Sunday. "The administration has hesitated between nonintervention and intervention, and it is caught between those two."
The Obama administration, Zakaria said, "seems to want to have it both ways, but it can't."
Others praised the president for taking a step to get more buy-in at home and abroad.
"Frankly, I think he looks prudent, and I don't doubt his resolve on this," John Negroponte, who served as director of national intelligence for two years under President George W. Bush, told CNN's State of the Union. "I don't think he's looking for an excuse to get out from a box or a situation that he painted himself into."
While some praised the president for giving Congress a chance to weigh in, a key group of Syrian dissidents said it was surprised and concerned by Obama's new approach.
"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," the Syrian National Coalition said.
Iran, a staunch supporter of the Syrian regime, warned the United States will pay a price if it strikes Syria.
The Syrian government has denied that it used chemical weapons in the August 21 attack, saying that jihadists fighting with the rebels used them in an effort to turn global sentiments against the regime.
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.
Syrian state media have been packed with critiques of the U.S. position since Obama's announcement Saturday. An editorial in the state-run Al-Thawra newspaper Sunday said that Obama had declared "the beginning of a historic American retreat."
Meanwhile, the opposition Syrian National Coalition issued a statement aimed at U.S. lawmakers.
"The Syrian National Coalition calls on the American congress to carry their historical responsibility towards the Syrian people and take the right decision to support the American government approach to stop the killing machine of the Syrian criminal regime," the statement said.
Sarin allegedly used previously in Syrian civil war