Brent crude climbed to a six-month high of $113 a barrel on Tuesday as Western powers readied a military strike against Syria to punish it for a poison gas attack.
Though Syria is not a major oil producer, Western intervention there could lead to a wider conflict in the volatile Middle East, which pumps a third of the world's oil.
Western officials told the Syrian opposition to expect a strike against President Bashar al-Assad's forces within days.
Brent crude was up $1.89 at $112.62 by 1240 GMT after trading as high as $113.03.
U.S. crude was up $2.16 at $108.08 a barrel, after falling 0.5 percent the previous day when data showed U.S. durable goods orders had dropped the most in nearly a year.
"As the rhetoric ratchets up around Syria the geopolitical risk premium in the price of oil is once again widening," Dominick Chirichella of Energy Management Institute said.
"Military action in Syria could result in a spreading of the chaos to the oil-producing areas of the Middle East as well as to some of the key shipping routes for crude oil."
The United States put Assad on notice on Monday that it believes he was responsible for using chemical weapons against civilians last week in what Secretary of State John Kerry called a "moral obscenity".
Also supporting oil, Libyan production has dropped nearly 60 percent to 665,000 barrels per day (bpd) due to a month-long disruption by armed security guards, who shut down main export terminals, its oil minister said on Tuesday.
In the United States, weak data on home sales and durable goods orders tempered views that the Federal Reserve could start paring its economic stimulus programme as soon as September.
The American Petroleum Institute will later on Tuesday release its weekly oil stocks data.
A preliminary Reuters poll showed that U.S. commercial crude stockpiles were expected to have fallen last week as refinery utilisation rates were at high levels, and gasoline inventories likely dipped primarily due to seasonal factors. (Additional reporting by Florence Tan in Singapore; editing by Keiron Henderson and Jane Baird)