WASHINGTON - The top U.S. general in Afghanistan said Thursday he wants to maintain a troop level of 68,000 after surge forces withdraw in October - his most revealing statement to date about U.S. troop strength for next year.

"We will need significant combat power in 2013," Gen. John Allen told the Senate Armed Services Committee. "Sixty-eight thousand is a good going in number, sir. But I owe the president some analysis on that."

Gen. Allen said he would announce a timeline of further troop withdrawals during the last quarter of this year but only after 23,000 surge forces leave the country.

Senators urged Gen. Allen not to make any recommendations that could risk progress already achieved by the troops.

"Now is not the time to quit. It is the time to recommit," said Sen. John McCain, Arizona Republican, urging the general to resist "short-sighted calls" for faster troop withdrawals. "There is still a realistic path to success if the right decisions are made in the coming months."