Oil prices rose to almost $81 a barrel supported by a weaker dollar and healthy Asian economic data.
For May delivery, US crude rose 61¢ to $80.61 a barrel by 3.52am ET, while London Brent crude gained 61¢ to $79.90, reports Reuters.
The dollar dropped nearly half a percent against a basket of currencies on Monday.
Strong economic data from Asia has raised optimism over the strength of the global economic recovery and a subsequent increase in demand for fuel lending support to oil.
A report by Organization of the Petroleum Exporting Countries expects oil prices to be in the $70-80 range over the next decade.