Updated

The top U.S. commander in Afghanistan said it will likely be the fall before he is ready to recommend how many troops the U.S. and its allies should keep in Afghanistan after combat troops leave in 2014 and what exactly their missions will be.

But Marine Gen. Joseph Dunford told reporters that NATO defense ministers meeting in Brussels may be able to provide guidance Wednesday on what nations will commit to maintaining a presence in Afghanistan, what parts of the country they might cover and how broad the training and advising mission should be.

His comments come amid sharp debate over whether the U.S. should be more specific about its long-term military commitment to Afghanistan, and suggestions by some defense experts that NATO's plan for a residual force of 8,000 to 12,000 may not be large enough. Last week, retired Gen. John Allen and a former undersecretary of defense urged the White House to announce its plan as soon as possible.

"I'm certainly not prepared today to tell you exactly what we'll need post 2014," Dunford said.

U.S. and NATO officials revealed the range of troops at their last meeting here in February, and officials say those numbers are still the working plan. U.S. officials have said President Barack Obama may agree to leave up to 10,000 U.S. troops in Afghanistan to help train and advise the Afghan security forces and continue counterterrorism operations against extremists, but the public has grown increasingly impatient with the nearly 12-year-old war that has cost thousands of lives and billions of dollars.

"I don't need specificity in numbers at this point," Dunford said. "What will be helpful to me is just get clarity and guidance on what it is that NATO wants to accomplish after 2014. And then I'll expect I'll be back here in six or eight months with a campaign assessment to talk about what progress we've made and then project out what we might need to do."

He said he wants to see how this year's fighting season goes and how well the Afghan's political process is advancing. He said he has argued that there should also be enough flexibility in the plans for commanders who will be there in 2015 and beyond.

Dunford said he has been struck by the progress that the Afghan security forces have made, noting that they are in the lead for military operations all across the country. He said their pace of combat is evident by the fact that they have had about 100 troops killed in each of the last two weeks.

Defense Secretary Chuck Hagel is attending the meeting of NATO defense ministers for the first time. Afghanistan is expected to be the main topic in Wednesday's session.

Dunford said that as the U.S. continues to negotiate its long-term presence in Afghanistan through a bilateral security agreement, it is more important to convince the Afghans that America's commitment will continue on years afterward.

It's been a tumultuous several months for Dunford in Afghanistan, where he has struggled to resolve difficult disagreements with the Afghan government over airstrikes, the transfer of detention facilities and the presence of special operations forces in certain areas.

And he warned Tuesday of more tough times ahead.

"In the coming months we'll continue to see the same kind of friction as we work through these issues that we've seen over the last couple of months," Dunford said. "But at the end of the day what's important is that we remain focused on the common objective that we have, which is stability and security in Afghanistan."

He added that there is "absolute unanimity in terms of where we want to be in 2015 and beyond. How we get there is where the friction, where the issues, are."

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