Obama facing pressure from all sides on Syria ahead of address President Obama's foreign policy was being challenged from all sides Tuesday as he prepared to address the nation on Syria, with Russia's Vladimir Putin pressuring Obama to drop his call for a military strike -- and members of the Syrian opposition warning that a newly emerging diplomatic option would only play into Bashar Assad's hands. The president and his administration on Tuesday were still approaching Syria on two tracks. Secretary of State John Kerry, during testimony on Capitol Hill, said the "ideal" solution would be for Syria to adhere to a proposal to turn over its chemical weapons to international control. Kerry plans to meet with his Russian counterpart in Geneva on Thursday to discuss the plan. Aides say Obama also was behind the surprise decision to delay a Senate test vote on authorizing the use of force, while the international negotiations play out. But Kerry still pushed Congress on Tuesday to approve a military strike, in order to keep the pressure on Assad. "We have to continue to show Syria, Russia and the world that we are not going to fall for stalling tactics," he said. In Russia, Putin reportedly needled the Obama administration to abandon the military option. Putin said the only way diplomacy can work is if "we hear that the American side and all those who support the United States in this sense reject the use of force," according to Reuters. But the diplomatic option was running into early obstacles, as an emergency meeting of the U.N. Security Council was suddenly called off, after Russia withdrew its request. And members of the Syrian opposition and others voiced concern that the chemical weapons plan is indeed turning into a "stall" tactic that will allow the Assad regime to escalate conventional warfare on its own people. Among the most outspoken since the emergence Monday of a potential U.S.-Russia plan has been the Syrian Coalition -- a leader in the nearly three-year-long effort to oust Assad. "It is vital to remember that the Assad regime, notwithstanding its use of chemical weapons, continues to use all kinds of conventional weapons against innocent women and children," said the group, formally known as the National Coalition of Syrian Revolution and Opposition Forces. The Assad regime, which has butchered people with knives and burnt them alive, has exhausted all time limits over the past two-and-a-half years. More than 100,000 Syrians have been killed in the civil war, including an estimated 1,400 in the sarin-gas attack last month that prompted Obama to conclude on Aug. 31 that the United States should launch a punitive strike and ask for congressional support. The diplomatic plan appeared to emerge Monday morning in London when Kerry said Assad has a long-shot possibility of avoiding a strike by surrendering the weapons. The plan was promptly endorsed by Russian Foreign Minister Sergey Lavrov, and by Monday night Obama appeared to make the idea part of his evolving foreign policy. "I welcome the possibility of the development," the president told Fox News. And John Kerry will be talking to his Russian counterparts. I think we should explore and exhaust all avenues of diplomatic resolution of this. But I think it's important for us to keep the pressure on. Syria's foreign minister embraced the proposal to turn over chemical weapons, saying Tuesday that Syria would declare its chemical weapons arsenal and sign the chemical weapons convention. Kerry, though, said Syria should "go further." Obama will give a prime-time White House address Tuesday, though it's unclear how robustly he will push for a military strike. Arizona Republican Sen. John McCain -- among Capitol Hill's most outspoken supporters of efforts to end the Assad regime -- said Tuesday he was "very skeptical" about the proposed diplomatic solution, considering Assad had refused to acknowledge having chemical weapons. Still, he said Congress should wait on deciding on a military strike until the possibility of a U.N. resolution on controlling Assad's chemical weapons "plays out." "To not pursue this option would be a mistake," McCain told CBS News before making clear he still thinks the best strategy is military support for Assad opposition forces to help overthrow the government. Meanwhile, Kansas Republican Rep. Mike Pompeo, a member of the Select Intelligence Committee, told FoxNews.com LIVE's "Power Play" on Tuesday the United States should still strike because the Syrian uprising is a national security concern. "I don't trust the president to execute this plan well," he said. It's why I wanted to engage. I was over at the White House yesterday. We had a very direct conversation about what the president ought to say tonight. But more importantly, what the president ought to do if he were to engage militarily in Syria. It's not enough to fire a couple missiles. Many in Congress, though, are against any U.S. military action in Syria. Senate Republican Leader Mitch McConnell on Tuesday joined those opposing a strike. It's not clear whether Congress will take up a resolution to authorize the use of force. Earlier in the day, House Democratic Leader Nancy Pelosi claimed there was no need for a congressional vote. "It is not necessary for Congress to give the president this authority," Pelosi said. We are grateful that he has asked for it but if he sees an opportunity we don't want the Russians to think that his leverage is diminished because of a vote (that) may or may not succeed within the Congress. The push-back from Washington and Moscow poses a challenge for Obama, as he finds himself caught between two very different paths on Syria -- a missile strike that potentially drags the U.S. into a bloody civil war, and a diplomatic solution that would likely do little to end that war. The momentum, at least temporarily, appeared to be running in favor of the diplomatic course. On Capitol Hill, a bipartisan group of eight senators started writing an alternative resolution that would call on the United Nations to state that Syria used chemical weapons and require a U.N. team to remove the chemical weapons from Syria within a specific time period, possibly 60 days. If that can't be done, then Obama would have the authority to launch military strikes, congressional aides said. The senators working on the proposal are Republicans John McCain, Kelly Ayotte, Lindsey Graham and Saxby Chambliss along with Democrats Chris Coons, Bob Casey, Chuck Schumer, Carl Levin and Bob Menendez.