July 16 (Reuters) - U.S. President Barack Obama’s request for more money to pay for the war in Afghanistan is working its way through Congress slowly as lawmakers concentrate on other priorities and deal with scarce budget resources.

Obama has asked for $33 billion more to help fund 30,000 extra U.S. soldiers being sent to Afghanistan this year. He wants $4.5 billion more for beefed-up foreign aid and civilian operations in Iraq and Afghanistan this year; about $2 billion of that amount is dedicated to Afghanistan.

The House of Representatives approved the funding last month and added billions of dollars in non-military spending, meaning the measure must return to the Senate for final approval.

Lawmakers are expected to pass the funds, but are also demanding assurances that the government of Afghan President Hamid Karzai tackles corruption to ensure U.S. taxpayer dollars are not wasted.

Following are the costs to U.S. taxpayers so far, as well as some of the future funding needed.

COSTS SO FAR

Congress has approved $345 billion so far for the war in Afghanistan, which the United States invaded to fight al Qaeda and topple the Taliban after the Sept. 11, 2001 attacks. The nonpartisan Congressional Budget Office, which produced the figure, said about $22 billion has gone for Afghan-war-related activities in other countries.

COMPARISON WITH IRAQ

Some $708 billion has gone to the Iraq war so far, CBO says. But Afghanistan is becoming the more expensive battleground, as the pace of U.S. military operations slows in Iraq and quickens in Afghanistan.

The current fiscal year, which ends Sept. 30, is the first in which more money has been allocated to Afghanistan ($72.3 billion) than Iraq ($64.5 billion), according to the National Priorities Project, a nonpartisan budget research group that examines congressional appropriations.

MONEY FOR AFGHANISTAN’S MILITARY AND POLICE FORCES

Included in the money spent on Afghanistan is more than $25 billion for training and equipping the Afghan National Security Forces -- the army and police, according to the Special Inspector General for Afghanistan Reconstruction. Obama wants another $14.2 billion for this purpose for the rest of this year and next; the idea is to leave behind security forces that can take on the responsibility of fighting the Taliban as U.S. forces start to leave.

FUTURE MILITARY COSTS

Future expenses are a question mark, partly because troop levels are uncertain. Obama says he wants to start withdrawing forces from Afghanistan in mid-2011, but that will depend on conditions on the ground. No departure deadline has been set.

Estimates of the cost per troop per year in Afghanistan vary from $500,000 to $1 million depending on whether expenditures on housing and equipment are included along with pay, food and fuel. Medical costs and veterans’ compensation balloon as time goes on.

FOREIGN AID AND CIVILIAN SURGE

Foreign aid, including food and development assistance, to Afghanistan has totaled some $17 billion since 2002, according to Department of State and Congressional Research Service documents.

Future expenses are unknown and there is growing concern among lawmakers over corruption in Karzai’s government.

Rep. Nita Lowey, a Democrat who heads the House appropriations subcommittee on foreign aid, last month froze about $3.9 billion in civilian aid to Afghanistan pending hearings on how Afghanistan and its U.S. partners intend to handle corruption.

The State Department is seeking more money to help fund a “civilian stabilization strategy” to deliver more economic assistance to Afghanistan, especially its agricultural sector. Part of the idea is to create jobs that will draw insurgents off the battlefield in Afghanistan. (Editing by Alan Elsner)