"Gen. Mattis and I have never talked specific numbers. I'm in the process now of answering some questions and making some recommendations," Dunford said.
Dunford said he met with Karzai on Saturday to discuss another issue between the two countries, the order by Karzai for U.S. Special Forces withdraw from Wardak Province, which is just west of the capital of Kabul, by this week.
There is still room for compromise, he said.
"His minister of defense was there, and we agreed to continue to work this issue with his minister, to ensure that we have adequate protection for the force, that we were gonna accomplish our security mission in Wardak, and also meet his concerns about moving Afghan forces in the lead," he said.