Oil prices have risen amid growing optimism that improved job creation in the United States will boost the economic recovery and lead to higher demand for crude.
US light crude reached $US85.31 per barrel on the first day of trading after the Easter break.
London Brent crude also rose to $US84.37 per barrel.
On Friday, the US Labor Department said employers created 162,000 new jobs in March, the highest monthly number since March 2007.
RBC Capital Markets vice president George Gero says the positive news has increased demand for several commodities.
However, the BBC reports oil prices are still a long way from the record of $US147.27 per barrel reached in July 2008.