Al-Qaida plots comeback in Afghanistan: US

"The United States will take the steps necessary to combat terrorism and protect our interests," she added.

Some administration officials have said that al-Qaida in Afghanistan is less of a threat than when the war began, estimated to be as many as several hundred forced to shelter in the remotest part of the country.

They say that al-Qahtani is so remote; he is nearly irrelevant to the larger al-Qaida movement. Two US intelligence officials say his group has been so cut off that it has been forced to rely on the Taliban for funding and weapons at times, where it used to be the other way around. Those officials are far more concerned about al-Qaida's new offshoots fighting in the Syrian civil war.

"It's really hard to get to New York City from northern Kunar or southern Nuristan", where al-Qahtani is based, said Douglas Ollivant, a former senior US military adviser in eastern Afghanistan, now with the New American Foundation.

"We do want to keep them bottled up there," he said, adding that that's something Afghan forces can do on their own. "The Afghan forces are not capable of going up there and hunting them, but they are capable of containing them," the former US military officer said.

Other experts see al-Qahtani and his kind as the main reason to push for at least a minimal security force in Afghanistan.

"There's an influx of Jihadist groups — not massive — now active in Afghanistan," said Seth Jones of the Washington-based RAND Corp., who once worked for US Special Operations Command in Afghanistan.

He listed the most dangerous as al-Qaida; the Pakistan Taliban; Lashkar-e-Taiba, blamed for the 2008 Mumbai terrorist attacks; and Harkat-ul-Jihad-al-Islami, which has strong links to al-Qaida.