Afghanistan is at a "critical juncture" that requires the Obama administration to consider backing off its plan to pull all U.S. forces out by the end of 2016, the commander of U.S. troops there told the Senate Armed Services Committee on Tuesday.

Under questioning by lawmakers, Gen. John Campbell was careful not to preempt President Obama's expected decision on whether to change the plan and would not specify the options he's presented to the White House for consideration.

But he did note that since the current plan was created in 2014, conditions on the ground had changed, including the election of a new Afghan government, stepped-up attempts by the Taliban to regain control and the appearance of the Islamic State on the Afghan battlefield.

When asked by Sen. Angus King, I-Maine, whether he thought the plan should be changed, Campbell replied: 'Yes, sir."

He also said Afghan President Mohammad Ashraf Ghani has asked coalition forces to remain in Afghanistan beyond 2016 to give his government more time to build stability.

"The Afghans welcome the opportunity to shape their destiny, but they still desire, need and deserve our assistance," Campbell said.

Though Afghan forces have fought well and were continuing to hold their ground this year, the Taliban takeover of the northern provincial capital of Kunduz highlighted their continuing shortcomings in the areas of intelligence, special operations and close air support, Campbell said.

"The Afghan security forces' inconsistent performance in this fighting season also underscores that their shortfalls will persist well beyond this year," he said.

Senate Armed Services Chairman John McCain, R-Ariz., who has been pressing Obama for months to abandon his withdrawal timetable, said the administration's plan "would invite the same tragedy that has unfolded in Iraq since 2011.

"It is not too late for President Obama to abandon this dangerous course and adopt a plan for U.S. troop presence based on conditions on the ground. But time is of the essence, and continued delays by the White House are hurting our national security interests and those of our partners in Afghanistan and beyond," he said.

"America's friends and foes alike are waiting on President Obama."

The U.S. has 9,800 troops in Afghanistan, of which 6,800 are part of the 13,000-strong NATO mission to train and advise Afghan forces. The others are focused on counterterrorism.

The administration has resisted calls by Republican lawmakers to slow or halt its withdrawal plan, but the Washington Post reported Monday that Obama is seriously considering a recommendation by Gen. Martin Dempsey, the former Joint Chiefs of Staff chairman, to keep up to 5,000 U.S. troops in Afghanistan beyond 2016.

On Monday, White House spokesman Josh Earnest would not confirm the report when asked about it or say when a decision would be announced. But Defense Secretary Ash Carter, in a news conference in Madrid with Spanish Defense Minister Pedro Morenes, said he expected Obama to decide this fall.

"I don't know what the president's final decisions will be, what decisions he'll make in that regard, but we continue to give him options," Carter said. "But I think the fundamental thing I want to stress is that there will be a U.S. presence and there will be a NATO presence in Afghanistan after 2016, no doubt about that. And there will be support to Afghan security forces as well."