Such a decision, if confirmed, would upend assumptions about a longer-term US military presence in Syria, which U.S. Defense Secretary Jim Mattis and other senior US officials had advocated to help ensure Islamic State cannot re-emerge.
Russia and Turkey reached an agreement last month to set up a demilitarized zone around the northwestern Syrian province of Idlib preventing a government offensive on the last rebel stronghold in the country.
Russia is not a member of G7 and will not be taking part in the meeting. German Chancellor Angela Merkel has been very critical of Russia's involvement in both Syrian and Ukraine conflicts and backs continued European Union sanctions against Moscow.
Almost 400,000 people in Eastern Ghouta are besieged by forces loyal to President Bashar al-Assad, and the United Nations has pleaded for his government to allow evacuation of around 500 patients, including children with cancer.
Since 2013, thousands of Uighurs, a Turkic-speaking Muslim minority from western China, have traveled to Syria to train with the Uighur militant group Turkistan Islamic Party and fight alongside al-Qaida, playing key roles in several battles.
On Syria, the two leaders discussed the importance of implementing United Nations Security Council Resolution 2254 and supporting the United Nations-led Geneva Process to peacefully resolve the civil war in that country.