Oil prices eased on Monday after hitting the highest levels seen since May as US President Donald Trump waived sanctions and tariffs on Russia, a move that could pave the way for higher Russian fuel exports.Crude oil price on October 19Brent crude futures dropped $1.80, or 1.64%, to $108.06 a barrel after settling at their highest level since May 19 on Friday. US West Texas Intermediate crude declined 53 cents, or 0.52%, to $100.88 a barrel.Trump signed an executive order on Friday suspending key sanctions and tariffs under the Graham Act, which he signed last month at the urging of lawmakers seeking to pressure Moscow over its war in Ukraine.However, Secretary of State Marco Rubio said the president would take up to 60 days to assess the economic impact of the waiver.