The national average U.S. retail price of diesel fuel dipped some from the previous average of  $1.763 to $1.761, the Department of Energy reported May 24.

Once again, the highest prices in the nation were in California, where the average cost is $2.266.

Among the higher prices were New England, at $1.806; $1.955 in the Rocky Mountain region; the Central Atlantic region, at $1.799; and on the West Coast, where the average price is $2.198.

Other prices include the Lower Atlantic region, where the average price is $1.658; the Midwest, at $1.687; the Gulf Coast, at $1.671; and the East Coast, at $1.707.

In the meantime, Saudi Arabia plans to boost oil production after other members of the OPEC deferred a decision on increasing the group's output quota, news services reported.

On Sunday, the world's largest oil exporter assured the United States that its request for increased supplies would be met, Bloomberg reported. OPEC is expected to decide whether to raise its production target when it holds a formal meeting June 3.