Obama on Wednesday said he is confident that Congress will authorize the strike adding the world had set "a red line" for Damascus and the international community’s credibility was at stake if it did not take action against Syria.

US President Barack Obama on Wednesday said he is confident that Congress will authorize the strike adding that the world had set "a red line" for Damascus and the international community's credibility was at stake if it did not take action against Syria.

Obama made the remarks after arriving in Sweden for a two-day visit, seeking to generate global backing for military action against Syria on top of his efforts at home to get bipartisan support for military strikes.

"I didn't set a red line. The world set a red line," Obama said in Stockholm, referring to international rules banning the use of chemical weapons, even in case of war.

"My credibility is not on the line. The international community's credibility is on the line and America and Congress's credibility is on the line because we give lip service to the notion that these international norms are important."

Obama's trip will also take him to the G20 summit in Russia's Saint Petersburg, where he is expected to rally support for or at least acceptance of moves to strike Syria.

White House officials have said Obama will hold meetings on the sidelines of G20 with the president of France, the main foreign backer of US strikes on Syria, as well as the leaders of China and Japan.

While no formal bilateral meeting is planned with Russian President Vladimir Putin, a strong supporter of Assad, a White House official suggested there likely would be some kind of dialogue.