The average price of gasoline in the United States rose again in the past two weeks, gaining nearly 3.5 cents to about $3.39 a gallon, due in part to higher crude oil prices, according to the nationwide Lundberg Survey.

The national average price for a gallon of regular gasoline went up 3.48 cents to $3.3944 a gallon as of Jan. 20, the survey of about 2,500 gasoline stations in the continental United States found.

That was a more modest rise than the 12-cent jump in the previous survey, which covered the three weeks ended Jan. 6.

The survey's editor, Trilby Lundberg, told Reuters that crises in Iran and Nigeria were putting pressure on crude oil supply. But because of dampened demand caused by Europe's debt crisis, it was hard to say which way prices would head.

Since crude oil prices rose a bit last week, Lundberg said gas prices could well increase another 5 cents or more in the short term.

Among cities covered, the lowest average was in Salt Lake City, Utah, where the price was $2.94 per gallon; the highest city on average was Los Angeles at $3.71 a gallon.