UN spokesman Martin Nesirky said the two will dine together on Thursday and “one could anticipate discussions on the main topics of the day and Syria is plainly one.”

Russia, the United States and the UN are working to set up a conference on Syria aimed at arranging a political transition, but have made little progress.

Russia is a key ally of the Syrian regime and has sought to protect it since the beginning of the conflict by blocking certain western resolutions at the UN Security Council.

US Secretary of State John Kerry and Defense Secretary Chuck Hagel, meanwhile, will meet their Russian counterparts on Friday in Washington.

Syria, the START nuclear disarmament treaty, Afghanistan, Iran and the Edward Snowden affair are on the menu for discussion, according the US State Department.