New York's main contract, West Texas Intermediate for delivery in October, edged down three cents to $107.53 a barrel, while Brent North Sea crude for October was unchanged at $111.50.
"The risk premium for Syria has come off but it's still there because the potential for military action has only dropped from more likely to less likely," said Kelly Teoh, market strategist at IG Markets in Singapore.
Investors are hoping Washington and Moscow will reach a deal that will see Syria hand over its chemical weapons and avert an attack from American forces.
US Secretary of State John Kerry is due to meet his Russian counterpart in Geneva as the two sides seek a diplomatic solution to the crisis, sparked by the Assad regime's alleged use of chemical weapons on its own civilians.
AFP