With gasoline topping 4 US dollars a gallon, US President George W. Bush has urged Congress on Wednesday to lift its long-standing ban on offshore oil and gas drilling.

Speaking in the White House, Bush renewed the call for lawmakers to lift the 27-year-old ban, saying the United States needs to increase its energy production.

"Congress must face a hard reality; unless members are willing to accept gas prices at today's painful levels - or even higher - our nation must produce more oil. And we must start now."

With the presidential election just months away, Bush made a pointed attack on Democrats, accusing them of obstructing his energy proposals and blaming them for high gasoline costs.

His proposal echoed a call by Republican presidential candidate John McCain to open the Continental Shelf for oil exploration.

Bush said offshore drilling could yield up to 18 billion barrels of oil over time, although it would take years for production to start.

He also said offshore drilling would take pressure off prices over time.