By David Alexander and Phil Stewart
WASHINGTON (Reuters) - The head of U.S. forces in Afghanistan said on Thursday he has presented his commanders with options on troop withdrawals in 2015, even as U.S. lawmakers accused the Obama administration of rushing to cut the U.S. military presence after 13 years of war.
Army General John Campbell told the Senate Armed Services Committee his options would offer U.S. leaders flexibility in how they withdraw forces during the year.
About 10,000 U.S. troops are currently in Afghanistan to train and assist Afghan forces, but the number is slated to drop to 5,500 by year's end.
A senior administration official said on Wednesday that Obama was considering a request from Afghan President Ashraf Ghani to slow the pace of withdrawals.
Lawmakers asked Campbell whether his options included leaving in place more troops after the end of the year, noting that retired Marine General James Mattis, a former head of U.S. Central Command, had recommended some 20,000.
"None of the options recommend an increase like that," Campbell said.
He said most options would offer greater flexibility on the pace and timing of withdrawals, as well as the locations from which forces would be pulled.
Republican Senator John McCain, who chairs the Senate panel, said Ghani told a U.S. congressional delegation at the Munich security summit over the weekend that current U.S. drawdown plans could jeopardize his country.
Obama's plan calls for reduction of U.S. forces in Afghanistan to just an embassy presence by the end of 2016.
"If we've learned anything from Iraq, it should be that wars do not end just because politicians say so," McCain said. "We cannot let the Taliban, al Qaeda and ISIS (Islamic State) conquer Afghanistan."
This summer's fighting season will be the first in which Afghan troops are "completely on their own," Campbell said. The U.S.-led international coalition withdrew most troops at the end of 2014, but left a small force to train Afghan troops and for counter-terrorism missions.
Afghan forces have led the fight against the Taliban for two years, with the international coalition in a supporting role. Campbell said Afghans had performed "quite well," but noted that they suffered a significant increase in casualties in 2014.
Ashton Carter, the nominee to be the next U.S. defense secretary, told his confirmation hearing last week he supported Obama's troop drawdown plan, but would be willing to review troop withdrawals if needed.