The price of oil has hit a six-month high after manufacturing data in the United States and China boosted confidence in the global recovery.
US light crude oil rose by $US2 a barrel, or 2.5%, to $US83.45 on Monday. London Brent rose $US1.90 to $US85.04 a barrel.
Figures showed that the US manufacturing sector accelerated faster than expected in October, thanks to strong orders and exports.
Manufacturing activity in China hit a six-month high in October.
Comments by Saudi Arabia's oil minister, Ali al-Nuami, also helped to boost the price of oil to its highest level since 3 May.
"I would say we are in a very comfortable zone that should continue for some time," Mr al-Nuami said.