By Missy Ryan

WASHINGTON (Reuters) - On the eve of this weekend's NATO summit, the United States remains short of its goal of raising $1.3 billion in security funds from its partners in Afghanistan, after a money-raising blitz failed to garner immediate contributions from allies coping with fiscal and political pressures.

Who will pay for Afghanistan's future security will be central when President Barack Obama hosts leaders from NATO and other nations in his hometown of Chicago for the May 20-21 summit that will outline the Western path out of the long war.

"There was some hope that the kitty would be full by Chicago. That may not happen but it doesn't mean we won't achieve that goal in the future," a U.S. official said.

The United States is believed to be some $300 million to $500 million short of its goal.

"We expect a number of countries to pony up, and that's a sign of progress toward sustaining (Afghan forces) in the years to come," the official said.

Western nations, grappling with fiscal crisis and mindful of dwindling support for the war, are eager to chart a course out of Afghanistan, even as the Taliban continues to pose a serious threat to the weak, corrupt Afghan government.

Afghanistan's growing national police and army are at the core of NATO's strategy for removing most foreign troops by the end of 2014 without triggering the collapse of its Western-backed government.

Keeping those forces armed and fighting in a country still heavily reliant on outside aid will cost an estimated $4 billion a year. To supplement American assistance, the Obama administration is asking its allies to provide $1.3 billion annually of that.

NATO Secretary General Anders Fogh Rasmussen, speaking in Brussels last month, said Chicago would not be a "pledging conference." But officials here had privately hoped to secure those commitments before the summit, which is seen as an opportunity for Obama to brandish his foreign policy achievements just months before the November elections.

With other earlier goals for Chicago - such as a once-hoped-for breakthrough in initial peace talks with the Taliban - on hold, a strong, clear outside commitment to funding Afghan forces takes on more importance for NATO leaders at the summit.


Pledges made publicly and privately toward the goal now amount to $800 million to $1 billion. Of that Britain, Germany, and Australia have announced annual support for Afghan forces worth about $400 million combined.

In addition, the Afghan government has committed $500 million annually.

A NATO official told reporters in Kabul this week that the alliance "hopes" the $4.1 billion total goal can be met in Chicago.

While more support may be unveiled in the coming days, not all nations the United States has tapped have been ready.

France, whose new President Francois Hollande has promised to accelerate the French departure from Afghanistan, is not expected to make a commitment at Chicago. "Financial commitments cannot be made here," a French diplomatic source said.

"The U.S. in some ways under-estimated the complexity of the decision-making process in other capitals" in its push to raise that money, one Western diplomat said on condition of anonymity.

"Although most ISAF members agree properly funding (Afghan forces) is critical, in the current fiscal and political climate, any new funding commitment is subject to an extensive debate. This meant it took longer to raise the funds than the U.S. anticipated," the diplomat said.

Obama dispatched his special representative for Afghanistan and Pakistan, Marc Grossman, to European capitals this spring to press for commitments. But funding requests may have not been made to countries early enough.

"The economic problems in Europe and the United States, combined with the continued concerns about corruption inside of Afghanistan, makes it an uphill battle to get countries to make long-term commitments on funding for Afghanistan," said Brian Katulis, a senior fellow at the Center for American Progress.

Japan, another important ally that will host a conference on aid to Afghanistan this summer, has not yet come forward. Neither have key Gulf allies Saudi Arabia and Qatar.

Even though the scenarios under consideration would cost the United States far less than it now spends in Afghanistan, the Obama administration itself will not be immune to pushback from its skeptical U.S. lawmakers, Katulis said.

The U.S. official said funding goals were expected to be met eventually.

"Everyone understands the stakes," the official said. "It would be a serious mistake to abandon Afghanistan like it was abandoned in 1989. We have a responsibility to support (Afghan forces)."

(Additional reporting by John Irish in Paris; Editing by Warren Strobel and Vicki Allen)