The Office of Management and Budget will meet with House and Senate Appropriations committee staffers on Thursday morning to layout details of a proposed $75.5 billion emergency spending bill for the Iraq and Afghanistan wars, Congressional aides said.

The closed-door meeting will mark the first official discussions between the administration and Capitol Hill on a detailed war-funding plan. A formal request will be sent to lawmakers later this week, after Thursday’s morning meeting with the appropriations staffers.

Already, lawmakers and the Obama administration are expected to spar over the size of the request. Rep. John Murtha (D-Pa.), chairman of the House Appropriations Defense Subcommittee, has said he would push to add about $16 billion to the supplemental request for a weapons program — a move opposed by the administration.

If approved, the latest request would bring the total fiscal 2009 war spending to $141.4 billion. The Pentagon has said it needs the money by Memorial Day or it will not have the funds to continue to pay for the wars.