U.S. import prices increased more than expected in May as the cost of petroleum products surged, the Bureau of Labor Statistics reported.

Prices for all imports rose 0.6% on a monthly basis in May, higher than Econoday's consensus estimate of 0.5%, but unchanged from the revised 0.6% increase in April.

Fuel import prices climbed 4.9% in May after a revised 4.1% increase in the previous month. Petroleum prices rose 5.9%, following a 4.4% increase in April, and crude prices went up 6.7%, following the prior month's gain of 5.9%.

Excluding fuel, prices for all imports increased 0.2% for the second straight month, boosted by higher prices for nonfuel industrial supplies and materials; consumer goods; and foods, feeds, and beverages.

"Ex-fuel, import prices continue to rise at a moderate rate and do not pose an immediate threat to more closely watched consumer inflation," said Sarah House, senior economist at Wells Fargo Securities.

Meanwhile, prices for all exports rose 0.6% in May, following a similar increase in April. Prices for agricultural exports advanced 1.6%, and prices for non-agricultural exports went up 0.5%.

The increase in prices for non-agricultural exports last month was due to higher prices for non-agricultural industrial supplies and materials, along with prices for capital goods and automotive vehicles.

In annual terms, prices for all imports rose 4.3% in May, and prices for all exports increased 4.9%.