The price of oil retreated from a two-year high Monday as the prospects of a U.S. attack against Syria remained unclear.

Benchmark oil for October delivery fell $1.01 to close at $109.52 a barrel on the New York Mercantile Exchange. On Friday, oil gained $2.16 to close at $110.53, the highest closing price since May 3, 2011.

President Barack Obama has called for military action against the government of Syrian President Bashar Assad in retaliation for what the White House says was a chemical weapons attack against civilians in suburban Damascus last month. But he has so far failed to win sufficient support for intervention both at home and abroad.

Obama plans to address the nation from the White House on Tuesday about Syria.

On a Monday, there was hope for a possible diplomatic solution when Syria's foreign minister welcomed a suggestion floated by U.S. Secretary of State John Kerry to move all the country's chemical weapons under international control.

The White House said it was taking a hard look at Syria's statement even as it redoubled efforts to sell the notion of the strike to a skeptical Congress and divided nation and senators prepared for a key test vote on the strike authorization Wednesday.

Meanwhile, at the gas pump, the average price for a gallon of gasoline remained at $3.57. That up a penny from a month ago, but down 25 cents from this time last year.

Brent, the benchmark for international crudes, dropped $2.40, or 2.1 percent, to $113.72 per barrel on the ICE Futures exchange in London.

In other energy futures trading on Nymex:

— Wholesale gasoline fell 5 cents to $2.80 per gallon.

— Natural gas rose 8 cents to $3.61 per 1,000 cubic feet.

— Heating oil retreated 5 cents to $3.12 per gallon.