US President Barack Obama said on Friday the expected US response to the Syrian regime\'s alleged rattack will be a message that those who use chemical weapons will not go unpunished.In a press conference after the conclusion of the G20 meeting in Russian city of St. Petersburg, Obama pointed out that most leaders of the G20 countries agree that Syrian President Bashar Al-Assad is responsible for using poison gas against civilians.\"The majority of the room is comfortable with our conclusion that Assad, the Assad government, was responsible for their use,\" he said.He underlined the Syrian regime\'s alleged use of chemical weapons impose a real threat to the security of its allies the Middle East, namely Israel, Jordan, Turkey, Iraq and Lebanon.Obama noted that the Syrian regime has breached the UN convention on the ban of chemical weapons use.He, however, underlined that the US is ready to consider all proposals for resolving the crisis in the Syria and avoiding military intervention.But no good proposals were raised so far, he said.The US President described his meeting with his Russian counterpart Vladimir Putin as constructive and frank.He disclosed that the Syrian crisis has dominated his talks with President Putin, but he added that he did not try to persuade Putin with the US point of view regarding the situation in Syria.Obama underscored that he and Putin are aware that the solution in Syria must be political not military.