WASHINGTON — The U.S. envoy in Afghanistan, a former Army general who once commanded troops in the country, has objected strongly to emerging plans to send tens of thousands of additional forces to the country, a senior U.S. official said Wednesday.

Ambassador Karl Eikenberry resigned his Army commission to take the job as U.S. ambassador in Kabul earlier this year, and his is an influential voice among those advising President Barack Obama on Afghanistan. Eikenberry sent multiple classified cables to Washington over the past week that question the wisdom of adding forces when the Afghan political situation is unstable and uncertain, said an official familiar with the cables. The official spoke on condition of anonymity to discuss internal administration deliberations and the classified documents.

Cables are diplomatic messages that may or may not be classified and carry greater heft than other forms of communication such as e-mail.

Eikenberry made the point that the administration should step cautiously in planning for any troop buildup while there are still so many questions surrounding Afghan President Hamid Karzai, the official said. Eikenberry is the front line U.S. official dealing with Karzai, the U.S.-backed leader whose administration was stained by corruption and mismanagement. It was a visiting senior senator, Democrat John Kerry of Massachusetts, who was instrumental in persuading Karzai last month to accept the findings of a U.N. panel that his re-election vote in August was too marred by fraud to stand.

Karzai agreed to a second round of voting but was elevated to a second term as president without a runoff election when his challenger dropped out. Since then, U.S. officials have been alarmed at some of Karzai's remarks and the lack, so far, of meaningful steps to clean house.

Eikenberry's objections were a wild card in the midst of what had appeared to be the final days of Obama's long decision-making process on how to revamp U.S. strategy in the 8-year war. Eikenberry has participated in some of Obama's war council sessions over the past several weeks.

A senior U.S. official told The Associated Press that Obama rejected all four options presented to him at what had been expected to be the last of those sessions Wednesday. Those options started from the premise that some addition of U.S. forces is necessary, and included ways that Obama could meet or nearly meet war commander Gen. Stanley McChrystal's preference for about 40,000 additional troops.

It is not clear whether Eikenberry's objections played a part in Obama's decision not to accept any of the choices prepared by military planners Wednesday.