The G20 summit in St Petersburg exposed stark divisions between host Vladimir Putin and US President Obama over Syria.
War emptied the suburb of Yarmouk in southern Damascus of its people. Assad's army holds it, but their prize is a ghost town.
Even in the President's heartland of Baltimore, 95% of voters are against his policy on military intervention in Syria.
The emir of Kuwait, Sheikh Sabah al-Ahmad al-Jaber al-Sabah, is due to visit President Obama in Washington on September 13 to discuss Middle Eastern issues, the White House said.
A statement said: "The President looks forward to discussing with the emir a wide range of critical interests and important developments in the Gulf region and broader Middle East."
The visit comes as Mr Obama seeks to gain Congressional support for punitive strikes against Syria in the wake of a chemical attack.
President Obama will address the US nation on Syria on Tuesday.
President Assad barely dented his stockpile of chemical weapons in an attack last month, the US ambassador to the United Nations claimed.
Samantha Power said: "We assess that although Assad used more chemical weapons on August 21 than he had before, he has barely put a dent in his enormous stockpile."
There is an extraordinary and dangerous demotion of the role of the United Nations as David Cameron and Barack Obama say that Syria policy cannot be left to the UN.
French President Francois Hollande said US President Barack Obama told him that a Congress vote on military action in Syria is expected in the middle of next week.
Leaders and representatives of 11 of the G20 leaders - Australia, Canada, France, Italy, Japan, Republic of Korea, Saudi Arabia, Spain, Turkey, the United Kingdom and the US - have made the following joint statement on Syria:
Signatories have consistently supported a strong UN Security Council Resolution, given the Security Council's responsibilities to lead the international response, but recognize that the Council remains paralysed as it has been for two and a half years.
The world cannot wait for endless failed processes that can only lead to increased suffering in Syria and regional instability.
We support efforts undertaken by the United States and other countries to reinforce the prohibition on the use of chemical weapons.
We commit to supporting longer term international efforts, including through the United Nations, to address the enduring security challenge posed by Syria’s chemical weapons stockpiles.
Russia was notably absent from the list of leaders.