Gen. John Allen, center, the chief NATO commander in Afghanistan, said the U.S. “will need significant combat power through the end of 2013.” (Alex Wong/Getty Images)

The top U.S. commander in Afghanistan on Thursday indicated that he believes there should be no American troop drawdowns in 2013, leaving the total at the 68,000 who will remain following scheduled withdrawals this year.

Pressed in a congressional hearing by Sen. John McCain (R-Ariz.), who has been critical of reports that the administration plans to continue withdrawals next year, Marine Gen. John R. Allen said: “My opinion is that we will need significant combat power through the end of 2013. . . . Sixty-eight thousand is a good going-in number,” he said, “but I owe the president some analysis on that.”

He said that no decisions have been made and that he would not prepare his recommendation to the White House until after the September departure of 23,000 surge troops who were added in 2010. He said it would be based on “the state of the insurgency” as well as “operational requirements for 2013.”

Allen’s comments moved beyond his testimony earlier this week, when he said only that he was confident that his views would be considered by the White House.

President Obama said last week that he expected withdrawals over the next two years to be gradual and that he did not want to encounter a “steep cliff” at the end of 2014, when all coalition combat troops are scheduled to leave under an agreement between NATO and the Afghan government.

There have been widespread reports, and accusations raised by Republican presidential contenders, that the administration is not heeding the advice of its military commanders in a war over which the American public has become weary and disillusioned. Recent opinion polls indicate that a majority of Americans want a faster drawdown.

Navy Capt. John Kirby, a spokesman for Allen, said there is “absolutely no daylight between General Allen and the commander-in-chief about the need to assess the state of the insurgency in the fall before making any decisions about future force levels.”

Asked about Allen’s testimony, White House spokesman Jay Carney said that Obama remained committed to withdrawal “at a steady pace” but that there are “no options currently under consideration.”

Allen also offered more specifics on reports last month, first published by the Wall Street Journal, that the military was considering a sharp decrease in the number of Afghan army and police forces to take over security functions after the 2014 deadline. The size of the Afghan force is projected at 352,000 by that point, and some donor countries have indicated a reluctance to continue paying for it.

The size of the future Afghan force will largely depend on “the funds that are going to be put on the table,” Defense Secretary Leon E. Panetta told reporters at a NATO meeting last month in Brussels.

Sen. Carl Levin (D-Mich), the committee chairman and a strong supporter of a robust Afghan force, described a possible reduction in the force as “penny wise . . . but pound foolish.”

Allen acknowledged that internal military studies that have examined the need for the force and its size through 2017 have concluded that 230,000 is the most likely size. He said that “we are continuing to evaluate” options he described as ranging “all the way from 352,000 down to lower than 230,000.”

But while those evaluations will continue, he said, “at this point, 231,000 to 236,000 looks to be the right number, in a combination of army and police capabilities.”

The coalition hopes to reach its 352,000 goal for the Afghan army and police this year. Some reports have put the cost of that force at $4 billion to $5 billon a year, although Acting Undersecretary of Defense James Miller, who testified with Allen, said the cost would be “more than that.”

Reducing the Afghan force to about 230,000, Allen said, would save between $2 billion and $3 billion a year in costs. The Afghan government’s current annual revenue is about $2 billion.