Retail gasoline prices in the United States have broken above $2 a gallon in some major cities amid plunging domestic fuel supplies and mounting fears over a possible war on oil supplier Iraq, according to a Reuters report. Prices are expected to continue to rise as spring approaches -- potentially breaking new records -- as driving demand traditionally picks up with warmer weather and pressures inventories, according to Reuters. The average retail price for regular gasoline in San Francisco was $2.044 a gallon on Feb. 19, while premium grades in cities like Los Angeles and Oakland were also above $2, according to the American Automobile Association. The national average price U.S. drivers paid for gasoline increased 5.3 cents a gallon over the last week to $1.66 a gallon, the seventh highest on record, according to a separate survey by the U.S. Department of Energy. Pump prices have risen along with higher crude oil costs, but some groups believe that fuel prices have risen higher than can be justified, setting off demands for an investigation by Federal Trade Commission, Reuters said.