NEW YORK - Ahead of next week's Donor Conference for Afghanistan in Paris, a leading American newspaper says that concern is growing that President Hamid Karzai is not up addressing his war-torn country's troubles. "After six years in which Hamid Karzai has been the darling of the United States and its allies, his luster may be fading," The New York Times said in a dispatch Saturday. Karzai plans to ask for $50 billion to finance a five-year development plan at the conference a donors conference with attendees from 80 countries, including Pakistan, and organizations. The plan is intended to revive Afghanistan's decrepit farming sector, promote economic development and diversify the economy away from its heavy reliance on opium. "But there is a growing concern in Europe, the United Nations and even the Bush administration that Mr. Karzai, while well-spoken, colourful and often larger than life, is not up to addressing Afghanistan's many troubles," the newspaper said in a dispatch from Washington. According to The Times, a senior State Department official questioned whether Mr. Karzai had the "trust and the backbone" for the job. "Of course he's a good guy, and therefore as long as he's president we'll support him," the unnamed official was quoted as saying. "But there's a lot of talk inside the administration saying maybe there's a need for some tough love to push him to do the right thing." One European diplomat, who was also not named, said, "We've got the standard administration problem of fascination with a flawed figure." The diplomat likened the support for Karzai to American backing for President Pervez Musharraf of Pakistan. American officials expressed particular frustration over the Afghan president's refusal to arrest drug lords who are running the country's opium trade, which many international observers believe the Taliban have used to fuel their comeback, the dispatch said. At both the State Department and the Pentagon, some officials are saying that President Bush should use the financial leverage of American aid to Afghanistan to demand that Karzai do more to crack down on corruption. One senior Bush administration official said that Bush remained enamored of  Karzai, according to the paper. Others questioned whether the White House would endorse a tougher line against him at a time when international forces in Afghanistan are continuing to face a resurgent Taliban, and when there are no obvious pro-American alternatives to Mr. Karzai among Afghan leaders. Still, Mr. Bush has sought to address some of the complaints. Two months ago he began holding twice-monthly video conference calls with his Afghan counterpart that are similar to his regular sessions with Nuri Kamal al-Maliki, the Iraqi prime minister. Asked to comment about Karzai, a White House spokesman, Gordon D. Johndroe, said, "President Bush appreciates the work that he's doing in Afghanistan, but we all know that there is more to be done." Afghanistan's ambassador to the United States, Said T. Jawad, defended Mr. Karzai's leadership and warned against pointing fingers at a fledgling government. "It's totally unnecessary to start a blame game," Jawad was quoted as saying.. According to American and European diplomats, recent tension has flared around an episode that received little attention outside Afghanistan and that involved Karzai's refusal to arrest a notorious Uzbek warlord, Gen. Abdul Rashid Dostum. General Dostum is said to have attacked a rival warlord with a beer bottle this year, almost killing him, and Afghan law enforcement officials sought to arrest him. But Karzai's government balked, according to Western diplomats and Afghan officials cited by The Times. The diplomats American and European - said that they urged Karzai to have General Dostum arrested but that he told them he did not want to pick a fight with General Dostum for fear of alienating his backers.