U.S. lawmakers' doubts ease on arming Syrian rebels: official By Susan Cornwell and Mark Hosenball WASHINGTON (Reuters) - The Obama administration has made progress in overcoming lawmakers' objections to its plans to arm Syrian rebels, but some details remain unresolved, a U.S. official said on Monday. Members of the Senate Intelligence Committee who questioned the wisdom of arming the insurgents have tentatively agreed the administration can go ahead with its plans, but asked for updates as the covert effort proceeds, a senior administration official told Reuters. There was no immediate comment from the committee. Nor was it clear whether any objections to the arms plan were still outstanding in the House of Representatives. After secret briefings by senior officials late last month, members of both chambers' intelligence committees had advised the White House to delay sending weapons to the rebels battling Syrian President Bashar al-Assad until congressional concerns were addressed. Both Republican and Democratic lawmakers fear the weapons could end up in the hands of Islamist militants, and would not be enough to tip the balance against the better-equipped Syrian government anyway. Vice President Joe Biden and Secretary of State John Kerry are among officials who have been lobbying Congress to try to assuage concerns. "We are in regular consultation with Congress on matters related to Syria assistance," said White House spokesman Jay Carney. A U.S. program to train the rebels that started months ago has also been challenged by a U.S. lawmaker who wants to know how the program is working out and where the administration thinks it should be headed. Some $27 million has been spent on the training program so far and over 800 people have been trained, congressional aides told Reuters. But the lawmaker and his staff recently asked for more information before another $1.3 million is approved for the project in Turkey, the aides said. Editing by Alistair Bell and Doina Chiacu