Oil prices are falling — gas prices aren't. Here's why.

U.S. motorists are likely to face higher gas prices for several weeks even if crude oil remains stable, according to GasBuddy petroleum analyst Patrick De Haan. Edited by Aimee Picchi In:

U.S. motorists are likely to face higher gas prices for several weeks even if crude oil remains stable, according to GasBuddy petroleum analyst Patrick De Haan.

Global crude prices swung wildly on Monday, soaring to nearly $120 a barrel earlier in the day before dropping after President Trump told CBS News that the U.S. war with Iran could end soon. 

Although Brent crude declined by about 13% on Tuesday, dipping to $85 a barrel, the national average gas price rose to $3.54 per gallon, or 6 cents higher than the previous day, according to AAA.

Gas prices have surged by more than 50 cents per gallon since the war started. The average price was $2.98 per gallon on Feb. 27, the day before the U.S. and Israel launched strikes on Iran, according to GasBuddy data shared with CBS News.

Motorists should expect to pay higher gas prices for the foreseeable future, De Haan told CBS News. Even if crude oil prices continue to fall, gas prices are unlikely to return to their levels before the Iran war began, partly due to seasonal issues that drive up fuel costs, he added.