On the New York Mercantile Exchange, light sweet crude futures for delivery in October traded at USD108.08 a barrel during U.S. trading, down 0.66%.
The October contract settled down 1.18% at USD108.80 a barrel on Thursday.
The commodity hit a session low of USD106.78 and a high of USD108.74.
Oil prices moved in a whipsaw fashion after Secretary of State Kerry said the U.S. has "high confidence" that Syria has used chemical weapons in its civil war and added that U.N. inspectors will only determine whether such weapons were used and but not discover who used them.
Kerry's words left investors worried the U.S. may launch a unilateral attack against Syria without the support of its allies and with no U.N. mandate, though uncertainty allowed for very choppy trading.
Elsewhere in the U.S., the Thomson Reuters/University of Michigan revised consumer sentiment index for August rose to 82.0. from a reading 80.0 in July, beating expectations for an uptick to 80.5.
Also in the U.S., a widely-watched Chicago purchasing managers' index rose to 53.0 this month from 52.3 in July, in line with expectations.
Friday's data rekindled expectations that the Federal Reserve may begin to taper its USD85 billion monthly bond-buying program in September as opposed to later in the year.
Monetary stimulus tools such as Federal Reserve asset purchases weaken the dollar by driving down interest rates, and talk of their dismantling strengthens the greenback and weakens oil and other commodities as a side effect.
Also Friday, the Bureau of Economic Analysis revealed that personal spending rose slightly less than expected in July, expanding 0.1% after an upwardly revised 0.6% increase the previous month. Analysts were expecting personal spending to rise 0.3% last month.
On the ICE Futures Exchange, Brent oil futures for October delivery were down 0.54% at USD114.54 a barrel, up USD6.46 from its U.S. counterpart.
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