WASHINGTON (CNN) -- More than 60 countries are expected to pledge close to $15 billion to rebuild Afghanistan at a donor's conference Thursday.
The United States will pledge the lion's share of over $10 billion, despite growing frustrations with President Hamid Karzai's leadership, State Department officials said.
The officials spoke on the condition of anonymity because they didn't want to upstage first lady Laura Bush, who is expected to announce the U.S. commitment at the conference in Paris, France.
State Department officials said that while the United States continues to believe that Karzai is the right leader for Afghanistan, there are some concerns about his leadership.
"There is a lot of buzz about Karzai both in Afghanistan and in the U.S. and elsewhere in the world that he is not as strong as he used to be, that he is not that charismatic forceful guy anymore, but maybe a man that might be tired," one official said. "There are a lot of cabinet battles he doesn't win and he has a difficult balancing act."
Since the U.S.-led invasion in 2001, the United States has provided $26 billion in aid to Afghanistan, U.S. Assistant Secretary of State Richard Boucher told reporters Thursday.
Karzai is expected to ask the international community for $50 billion in aid over the next five years for his long-term development strategy for the country, Boucher said Tuesday.
Despite a 65,000-troop-strong international presence in Afghanistan, the U.S.-backed Karzai government has struggled to extend security control over much of the country and continues to battle a Taliban resurgence.
Karzai has faced worldwide criticism for failing to combat a rampant corruption problem. On Tuesday, the World Bank issued a report charging that the government's infighting and lack of leadership "has resulted in the widely held view that corruption is being ignored or tacitly allowed."
The international community wants to streamline aid and boost Afghanistan's ability to manage reconstruction projects, hire Afghan contractors and root out corruption, Boucher said.
Donors in Paris will be eager to hear about Karzai's plans to combat corruption and improve financial transparency, he said.
"We'll look to see what the Afghans are able to say on that when they get to Paris, frankly," Boucher said. "That'll be an important point for us all."
Asked about U.S. confidence in Karzai, Boucher gave a lukewarm response.
"President Karzai is the elected president of Afghanistan. He's a man we work with," Boucher said. "The whole goal of this process was to allow the Afghans to choose their government. They've done that."
Boucher acknowledged that more needed to be done, but pointed out progress in construction of roads and electricity grids in parts of the country. He said criticism at the pace of development is unfair because of the dire state Afghanistan was in for nearly half a century before the U.S.-led invasion.
"We're talking about construction in many cases, not reconstruction." Boucher said. "We've been starting from nothing or less than nothing and built an Afghanistan now that's seen as a nation where the government has capabilities to be able to do things around the country, but not yet everywhere in the way we would like."
In March, NATO countries pledged at their annual summit in Bucharest, Romania, to help boost Afghan security amid concerns that poor security was hampering development.