A summit of the Group of 20 (G20) developed and developing economies is due to open on September 5 in the northern Russian city of St. Petersburg, reports Radio Free Europe, Radio Liberty. The G20, which accounts for 90 percent of the world's economic output, will hope to reach agreement on growth, trade, banking transparency and fighting tax evasion during their two-day meeting. Russia's position as host marks the first time a member of the rising BRICS group of nations -- Brazil, Russia, India, China and South Africa -- will have staged the G20 summit. Syria is not on the summit's official agenda, but is expected to figure highly in talks as U.S. President Barack Obama is likely to push the case for military action to punish Damascus for an alleged chemical attack. Moscow doubts Washington's claims that Syrian forces used sarin gas against civilians in the suburbs of Damascus on August 21, killing some 1,400 people. On the eve of the summit, Obama said he would continue to try to convince Putin of the claims. "Do I hold out hope that Mr. Putin may change his position on some of these issues?" Obama said in Stockholm. "I'm always hopeful, and I will continue to engage him because I think that international action will be much more effective and ultimately, we can end deaths much more rapidly, if Russia takes a different approach to these problems," Obama said. Syria is one of a growing number of issues putting Washington at odds with Moscow. As reported earlier, Obama is not holding a bilateral meeting with Russian President Vladimir Putin at the summit after scrapping a much-anticipated visit to Moscow over Russia's decision to grant temporary asylum to U.S. intelligence leaker Edward Snowden.