Diesel and gasoline prices continued to tick upwards in the U.S. this week due to a spike in oil prices fueled largely by concerns of the continuing crisis in the Ukraine.

According to data tracked by the Energy Information Administration (EIA), the average retail pump price for diesel increased 1.9 cents to $3.971 per gallon this week; a price that’s 8.4 cents per gallon higher compared to the same week in 2013.

Diesel prices increased in every region of the country, the agency said, except for New England, where prices declined 8/10ths of a penny to $4.212 per gallon, and the Central Atlantic, where diesel dropped 2/10ths of a penny to $4.191 per gallon.

Those two regions, along with the West Coast (up 4.9 cents to $4.030 per gallon), California ($4.102 per gallon) and the East Coast ($4.070 per gallon), all registered diesel prices over the $4 per gallon mark, according to EIA.

The average retail pump price for gasoline in the U.S. also increased this week by 3.2 cents to $3.683 per gallon, which is 14.7 cents per gallon higher compared to the same week in 2013, the agency noted.

The West Coast exceeded the $4 per gallon mark, as gasoline increased 5 cents to $4.027 per gallon, though when excluding California, prices increased 4.9 cents to $3.719 per gallon.

Gasoline prices increased in all regions of the country, EIA noted, with the highest spikes in the Central Atlantic (up 6.3 cents to $3.674 per gallon), the Lower Atlantic (up 4.6 cents to $3.645 per gallon), New England (up 4.7 cents to $3.685 per gallon), and the East Coast (up 5.3 cents to $3.662 per gallon).

The agency added that higher oil prices are helping push up the cost of diesel and gasoline, noting that North Sea Brent crude oil spot price in March averaged near $110 per barrel (bbl) for the ninth consecutive month, while West Texas Intermediate (WTI) crude oil prices remained flat near $101/bbl.

The discount of WTI crude oil to Brent crude oil – which averaged more than $13/bbl from November through January – fell to $7/bbl in March, and EIA expects the WTI discount to average $9/bbl in 2014 and $11/bbl in 2015.

During the April-through-September summer driving season this year, the agency expects regular gasoline retail prices to average $3.57 per gallon, with the projected monthly national average regular retail gasoline price falling from $3.66/gal in May to $3.46/gal by September.

EIA expects regular gasoline retail prices to average $3.45/gal in 2014 and $3.37/gal in 2015, compared with $3.51/gal in 2013. Based on the market value of futures and options contracts for this key petroleum component of gasoline, there is a 3% probability that its price at expiration will exceed $3.35/gal, the agency cautioned, which is consistent with a monthly average regular-grade gasoline retail price exceeding $4.00/gal in July this year.