U.S. President Barack Obama said there's no doubt Syria used chemical weapons on its own civilians and he wants to launch attacks, but he first wants to get Congress' approval after lawmakers come back from recess September 9. The Middle East "is a powder keg" that will explode if Syria is attacked, Syrian President Bashar al-Assad told French newspaper Le Figaro in an interview published in part Monday. The Obama administration will conduct classified briefings regarding Syria for Congress almost every day this week, CNN's Dana Bash has learned. Secretary of State John Kerry told House Democrats in a phone call Monday that Turkey, Saudi Arabia and the United Arab Emirates have offered military assets for any action planned for Syria, two sources on the call told CNN's Dana Bash. Kerry also said more countries will move toward supporting such action. The sources said 127 Democratic lawmakers were on the 70-minute call with Kerry, National Security Adviser Susan Rice, Defense Secretary Chuck Hagel and Chairman of the Joint Chiefs of Staff Martin Dempsey. Kerry will testify before congressional committees Wednesday, congressional sources said. He will testify to the House Foreign Affairs Committee. He and Director of National Intelligence James Clapper will testify in a classified briefing for the Senate Foreign Relations Committee. Sens. Harry Reid and Robert Menendez, two top Democrats, are working to narrow the scope of President Obama's proposed authorization to use force in Syria, a Democratic leadership source said Monday. There have been concerns that the original draft doesn't have an expiration date and doesn't explicitly prohibit forces on the ground. Several U.S. Navy ships are now in the Red Sea, a U.S. official said Monday. A second official said the aircraft carrier USS Nimitz is not expected to participate in combat operations over Syria, but that the ship is there for a greater U.S. military presence in the region. U.S. Defense Secretary Chuck Hagel will testify about "military strategy and justification for the use of force" at Tuesday's Senate Foreign Relations Committee hearing on Syria, a U.S. official told CNN. The official spoke on condition of anonymity because the official announcement had not yet been made. Secretary of State John Kerry will testify Tuesday at the Senate Foreign Relations Committee hearing on Syria, a Senate Democratic source said Monday. NATO Secretary General Anders Fogh Rasmussen said he thinks a "strong response to the use of chemical weapons is needed." But, he told reporters in Brussels on Monday, he doesn't "see a long-term sustainable military solution" to the Syrian conflict and stressed the need for a "political process." Rasmussen said he's "convinced that the Syrian regime is responsible" for a chemical attack last month. He said "many facts" point to that conclusion. Asked about alleged chemical weapons use in Syria, Rasmussen said there needs to be a firm international reaction to avoid future chemical attacks. "It would send a very dangerous signal to dictators all over the world if we stand ... by and don't react," he said. The question is how to react and when to react. NATO is playing its part in the crisis in Syria through the deployment of Patriot missiles in Turkey for protection of that country's population, Rasmussen told reporters Monday. But if Turkey, a NATO member, is attacked, allies would have to gather and discuss how to respond. "We are prepared to defend Turkey effectively," he said. The pro-regime Syrian Electronic Army appears to have hacked the U.S. Marines recruitment website, marines.com, and posted a letter urging Marines not to attack Syria. Russia says it doesn't buy U.S. claims that the Syrian regime used chemical weapons. Russia plans to send a delegation of lawmakers to the United States to meet with members of Congress over Syria, Russian state-run news outlet RIA Novosti reported Monday, citing a top parliament member. CNN's Joe Sterling, Mohammed Jamjoom, Saad Abedine, Mohammed Tawfeeq, Yousuf Basil, Josh Levs, Holly Yan, Dana Bash, Tom Dunlavey, Reza Sayah and Catherine E. Shoichet contributed to this report.