Oil prices increased Sunday into Monday after President Trump rejected a proposal by Iran to end its months-long military conflict with the U.S. – the latest change in a global energy market in which prices have either increased or decreased depending on events that suggest the war will continue or end. 

The price for American benchmark was $98.27 per barrel on Monday morning, down from over $100 per barrel Sunday night but climbing Monday.

The increase follows prices falling to close to $90 per barrel after the U.S. sent a proposal to Iran that would have ended the war. 

The average gasoline price in the U.S. was $4.52 a gallon Monday, up from $4.46 a gallon last week, $4.14 last month and $3.14 a year ago, according to AAA.

Energy Secretary Chris Wright warned Sunday morning on CBS's "Meet the Press" that he wouldn't rule out average gasoline prices in the U.S. topping $5 a gallon.