WASHINGTON (Reuters) - The Obama administration is expected to announce by Wednesday its updated plan for oil and natural gas drilling in U.S. waters, including whether to allow exploration for the first time along the U.S. East Coast.

Workers drill for oil at an oil derrick in Los Angeles October 24, 2006. REUTERS/Lucy Nicholson

The plan could pave the way for a significant new domestic source of energy, helping to reduce U.S. dependence on oil imports and boost supplies of natural gas used to displace coal in power plants as the country works to reduce emissions of climate-changing greenhouse gases.

Last month, Interior Secretary Ken Salazar said he wanted to release the updated drilling plan by the end of March.

Two industry sources said on Monday President Barack Obama was expected to give a speech about energy security on Wednesday, which could include his views on expansion of offshore drilling.

The Interior Department and White House declined comment on Monday on whether Obama would speak to the issue in a speech slated for mid-morning on Wednesday at Andrews Air Force Base in Maryland.

The administration has been weighing the pros and cons of offshore drilling since it took office and put the brakes on a Bush-era proposal that called for drilling along the East Coast and off the coast of California.

For more than 20 years, drilling was banned in most offshore areas of the United States outside the Gulf of Mexico because of concerns spills could harm the environment.

Congress allowed the prohibition to expire in 2008 and former President George W. Bush lifted a drilling moratorium that year.

Environmental groups and some lawmakers continue to raise concerns about the impact increased drilling would have on coastal areas.

But Obama, who wants Congress to move a stalled climate change bill, has sought to reach out to Republicans by signaling he is open to allowing offshore drilling, providing coastlines are protected.

The U.S. Geological Survey estimates the U.S. Atlantic coast waters may hold 37 trillion cubic feet of gas and nearly 4 billion barrels of oil, while the Pacific Coast has 10.5 billion barrels of oil and 18 trillion cubic feet of gas.

To put that in context, the United States imports about 2 billion barrels of oil a year from OPEC nations and is expected to import 2.7 trillion cubic feet of natural gas from all sources this year, according to the Energy Department.

The administration’s plan is expected to spell out whether and when drilling will be allowed in 3 million acres off the Virginia coast.

The Bush administration had proposed leasing the Virginia tracts to energy companies and said the government would receive bids for the leases in November 2011.

However, a senior Interior official told an oil industry conference in January that drilling off Virginia’s coast would definitely be delayed past the original 2011 leasing date.

The proposed Virginia lease area, located about 50 miles from shore, may hold 130 million barrels of oil and 1.14 trillion cubic feet of natural gas.

The possible delay in drilling off Virginia’s coast has been criticized by the state’s new governor, Republican Bob McDonnell, and two U.S. senators eager for the state to tap into the jobs and royalties that come with exploration.

A spokeswoman for McDonnell said his office has not been told the updated drilling plan would be announced on Wednesday.