WH goes all-out to win Syria strike support ahead of Tuesday speech 5, 2013: President Obama attends a working session of the G20 Summit in Constantine Palace in Strelna near St. Petersburg, Russia.REUTERS The Obama administration is making an all-out effort to win Americans' support for a military strike against Syria ahead of the president's scheduled Oval Office speech on Tuesday. White House Chief of Staff Denis McDonough will begin the full court press by appearing on the Sunday morning talk shows to continue to make the president's case that Syrian President Bashar al-Assad ordered a chemical-weapon attack last month that killed more than 1,400 of his own people and that the United States must take punitive action. The major public push comes ahead of the Senate vote as early as this upcoming week. The President has watched as members of his own party have balked at his call for a strike, with the latest being moderate Democratic senator Mark Pryor of Arkansas. Pryor released a statement on Saturday saying the administration has not demonstrated that getting involved in Syria is in the country's national interest. "I cannot support military action against Syria at this time," Pryor said. Obama said Aug. 31 that he had decided the U.S. should act but also said he wanted congressional support, which has already resulted in numerous classified briefings at the White House and on Capitol Hill and Secretary of State John Kerry testifying publicly at two congressional hearings earlier this week. A senior administration official told reporters this weekend the push to win public support will also include National Security Adviser Susan Rice making a speech at the New America Foundation on Monday. The speech will take place the same day another classified briefing is scheduled for the House, the chamber in which Democratic and Republican congressional members appear most skeptical of a strike, despite large support from Capitol Hill leadership. Also on Saturday, the White House announced the president will do a round to interviews Monday afternoon with CNN, Fox, PBS and the three major networks that will be taped, then aired on their evening news broadcasts. And a DVD related to last month's chemical weapon attack -- which was shown Thursday to the Senate Select Committee on Intelligence in a classified briefing -- was circulating publicly Saturday. A source tells Fox News parts of the videos can be found on YouTube and that the CIA compiled the images and put them on the DVD. The videos were purportedly shot by pro-opposition forces in Syria. With the exception of France, no other countries have supported the U.S.' plan for a military strike. But this weekend, the European Union agreed the Aug. 21 chemical weapon attack outside Damascus appears to have been the work of the Assad regime but also said any potential military attack against it should wait for a U.N. inspectors' report. After meeting with Secretary of State John Kerry, the EU ministers ended days of division on the issue at the G-20 summit in St. Petersburg, Russia, with a common statement Saturday that the available intelligence "seems to indicate strong evidence that the Syrian regime is responsible for the attack," EU foreign affairs chief Catherine Ashton said. Germany joined in blaming the attack on the Syrian government. It had been the only European member of the G-20 not to co-sign the statement. The statement calls for a strong international response against Assad's regime but stops short of explicitly calling for military action against the Syrian government. On Friday, French President Francois Hollande qualified his country's support, saying the country would wait for the U.N. report before deciding to intervene militarily. Meanwhile, McDonough, Kerry and Vice President Joe Biden continue to call members of Congress. And McDonough is taking to the House Democratic Caucus on Tuesday morning, before Obama's statement, the administration official told reporters returning from the G-20 summit. The official also said the list of countries that signed the EU agreement shows broad international support for the U.S. even if the countries don't participate operationally and that the statement includes everything the White House wanted.