Washington (CNN) -- President Obama is considering four scenarios to move forward in Afghanistan and is expected to discuss them at his eighth meeting with his war council on Wednesday afternoon, sources told CNN.

Though the options are not being spelled out, one is fairly well-defined.

That option, a senior administration official and U.S. military official independently confirmed, calls for sending about 34,000 U.S. troops to Afghanistan.

A military official said the plan would send three Army brigades, totaling about 15,000 troops; a Marine brigade, about 8,000 troops; a headquarters element, about 7,000 troops; and 4,000 to 5,000 support troops.

The troops would be spread across the country, mainly focusing in the south and southeast, where much of the fighting is.

The military official said the option has been a favorite at the Pentagon in the past few weeks to send to the president.

The combat brigades would be brought in gradually, in three-month intervals.

That is one option, the senior administration official emphasized, saying the president had not decided.

The other options, the official said, would be "different mixes," or "different components of it."

On Wednesday, the president will address a number of issues with his war council, beyond how many troops to send. Obama also is expected to consider the kind of cooperation the United States can expect from the government of Afghan President Hamid Karzai, the kind of civilian support the United States is willing to offer, and the kind of support the United States can expect from other countries, the senior administration official said.

All those factors could lead to "further refinements" or some "greater elements being considered," the official said.

"He's got to fine-tune this, put it all together ... for what direction best advances our interests," the official said.

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."

White House officials would not say whether Wednesday's meeting with the war council would be the president's final meeting before deciding on Afghanistan, but they did say he would continue to discuss the war effort in smaller groups, including when he travels to Asia. He leaves Thursday.