U.S. military troops at war in Iraq and Afghanistan would receive one-week's pay instead of two in their next paycheck if the government shuts down this weekend due to the federal budget impasse, according to a senior defense official.

The official, who spoke on condition of anonymity to discuss personnel issues, said the military can't be paid during a funding lapse until a new appropriations bill or continuing resolution is passed by Congress.

If the funding bill expires on April 8, it will be in the middle of the military's two-week pay period, so Pentagon would send out paychecks for just the first week of the pay period, said the official,

Historically, workers such as the military who are required to work are legally obligated to eventually receive pay for it.

Additional details on the military's plan for funding during a potential shutdown are expected in the next day or so.

Pentagon press secretary Geoff Morrell said earlier Tuesday that department leaders hadn't figured out how pay would be affected for the military, including the 146,000 service members in Iraq and Afghanistan

Morrell said the Pentagon would continue key national security responsibilities including fighting the Afghanistan and Iraq wars, and continuing operations in Libya and earthquake assistance to Japan.

President Barack Obama says the administration and Congress are closer to an agreement on the budget than ever before. Officials are trying to hammer out an agreement that could cut billions from the estimated $1.2 trillion budget for 2011.