WASHINGTON — The Pentagon is seeking more than $20 billion in its 2009 budget to increase the size of the Army and Marine Corps as the military struggles to fight wars on two fronts, according to documents obtained by The Associated Press.

The proposed budget, which will be unveiled today, will call for $15.5 billion to boost the size of the Army by 7,000 soldiers, to a total of 532,400. And it will propose spending $5 billion to add 5,000 Marines to the Corps, for a total of 194,000.

Separately, the budget will call for nearly $11 billion to cover the costs of training, recruiting and retention.

Both services have been strained by the wars in Iraq and Afghanistan, prompting Pentagon leaders to seek money to increase recruiting and bonuses in a broad effort to add soldiers and Marines.

The funding is part of the Defense Department's overall $515 billion request for the budget year beginning Oct. 1 that President Bush will send to Congress. That is a $35 billion increase — or 7.5 percent — over this year's funding level.

Service members would get a 3.4 percent pay raise as part of the budget plan. Army personnel costs would eat up more than a third of its proposed budget, or nearly $52 billion.

Plans are to increase the number of the active duty Army, Army National Guard and Army Reserve by 74,000 overall, with the active duty force growing by 65,000 to a total of 547,000. Army leaders plan to complete the increase by 2010, and about half of the 65,000 has already been achieved.

The Pentagon budget would fund a force of 2.2 million in the Army, Air Force, Navy and Marines. It also calls for $70 billion as an initial down payment to cover the costs of the war for the fiscal year.

Spending on aircraft, weapons, and research and development defensewide would total close to $184 billion, an increase of less than 5 percent over the current year.

The Army alone is requesting $24.6 billion for weapons and aircraft programs, an increase of $2 billion over its current spending level.

Funding will also be sought for one Virginia-class submarine, an aircraft carrier, a destroyer and several other combat and cargo ships for the Navy; a broad array of unmanned aircraft; and $10.5 billion for missile defense.

The Army's total budget request for 2009 is $140.7 billion, up from $130.2 billion in this current year.

Increasing the number of soldiers will also boost construction costs for the Army. More than $3.7 billion of the Army's proposed $6.8 billion military construction and family housing budget would be earmarked for facilities to accommodate the growing force.