KABUL, Afghanistan (CNN) - Afghan President Hamid Karzai's office contacted the U.S. ambassador to Afghanistan about reports the envoy warned against sending more U.S. troops to the country, a Karzai spokesman told CNN Thursday.
Ambassador Karl Eikenberry's office would not confirm the reports to Karzai's office, Karzai spokesman Seyemic Herawi said.
Karzai will not comment on the reports without more information from the U.S. embassy, Herawi said.
Eikenberry's reservations were reportedly spelled out in cables sent to U.S. President Barack Obama last week. Eikenberry has previously expressed worry about corruption in Karzai's government and its ability to partner with the United States to fight the Taliban.
A senior State Department official told CNN that the Obama administration has questions about Karzai's behavior, suggesting that it has been inconsistent.
Asked for an official response on reports of the cables, the U.S. Embassy in Kabul said it does not comment on private messages, but did confirm that there had been correspondence between Eikenberry and the president.
Earlier, White House spokesman Tommy Vietor said, "We won't discuss classified documents publicly, but, as we have said for months, success in Afghanistan depends on having a true partner in the Afghan government."
Initial reports of cables sent by Eikenberry appeared in the New York Times, Washington Post and Los Angeles Times. All three attributed the reports to senior U.S. officials, without identifying them.
The developments came as Obama told his war council Wednesday that the U.S. troop commitment to Afghanistan is not open-ended, and then asked for revisions to options he previously received for sending more troops, a senior administration official told CNN.
The war council - comprising top Cabinet, Pentagon and administration officials - met with Obama for the eighth time to discuss a request by the top U.S. commander in Afghanistan for up to 40,000 more troops. The meeting lasted more than two hours, according to the senior administration official.
"The president and his team discussed the length of time that it would take to implement the options he's been presented," the senior official said. "The president believes that we need to make clear to the Afghan government that our commitment is not open-ended. After years of substantial investments by the American people, governance in Afghanistan must improve in a reasonable period of time to ensure a successful transition to our Afghan partner."
In particular, Obama pushed for revisions in proposed plans for troop increases to clarify how and when U.S. troops would turn over responsibility to the Afghan government, the official said.
The president's questions at the meeting could determine how many troops eventually are sent to Afghanistan, as well as how long they would be there, according to the senior administration official.
Earlier, a senior administration official and a U.S. military official independently told CNN that one option presented to Obama calls for sending about 34,000 more U.S. troops to Afghanistan, in addition to the 68,000 already committed to the country.
The military official said the plan would send three U.S. Army brigades, totaling about 15,000 troops; a Marine brigade of about 8,000 troops; a headquarters element of about 7,000 troops; and 4,000 to 5,000 support troops. The combat brigades would be brought in gradually, in three-month intervals, according to the military official.
The troops would be spread across the country, mainly focusing in the south and southeast, where much of the fighting is, according to the military official. The option has been a favorite at the Pentagon in recent weeks, the official added.
That is only one option, the senior administration official emphasized. Three other options, the official said, would be "different mixes," or "different components of it."
Despite reports to the contrary, Obama has not decided the number of U.S. troops he will send to Afghanistan, White House officials said.
Such reports are "absolutely false," Press Secretary Robert Gibbs said. And anyone who suggests otherwise, "doesn't have, in all honesty, the slightest idea what they're talking about."
Republican members of the Senate Armed Services Committee urged Obama in a letter sent Wednesday - Veterans Day - to agree to the request for additional troops by U.S. military leaders in Afghanistan.
The letter, signed by 10 Republican committee members, said success in Afghanistan will require local leaders and citizens being able to govern and secure their country without substantial international assistance.
- CNN 's Suzanne Malveaux, Mike Mount, Chris Lawrence and Tom Cohen
contributed to this report.