WASHINGTON, Nov. 12 (Xinhua) -- The U.S. ambassador to Afghanistan opposes a pending buildup of U.S. forces in that country, the Washington Post reported Thursday.

    Ambassador Karl W. Eikenberry sent two classified cables to Washington in the past week, expressing deep concerns about sending more U.S. troops to Afghanistan until "Afghan President Hamid Karzai's government demonstrates that it is willing to tackle the corruption and mismanagement that has fueled the Taliban's rise," the Post reported, quoting official sources.

    Eikenberry's attitude threw weight into President Barack Obama's ongoing deliberations over a new Afghanistan strategy, which have entered the final stages.

    It also illustrated a deepening division amongst key U.S. policymakers on the issue.

    After a top-level meeting on Afghan strategy Wednesday afternoon -- Obama's eighth since early last month -- the White House issued a statement that appeared to reflect Eikenberry's concerns.

    "The president believes that we need to make clear to the Afghan government that our commitment is not open-ended," the statement said.

    "After years of substantial investments by the American people, governance in Afghanistan must improve in a reasonable period of time," it said.

    On the eve of his nine-day trip to Asia, Obama was given four options laid out by military planners with differing numbers of new U.S. deployments, ranging from 10,000 to 40,000 troops.

    None of the scenarios calls for scaling back the U.S. presence in Afghanistan or delaying the dispatch of additional troops.

    But administration officials said Thursday that Obama has asked his top aides to refine the four options "to clarify how and when U.S. troops would turn over responsibility to the Afghan government."