KABUL, Afghanistan >> The top U.S. commander in Afghanistan has been ordered to submit a plan by mid-October for the initial withdrawal of American troops, the chairman of the Joint Chiefs of Staff said Sunday. That plan may hinge in part on whether the latest surge in attacks continues through the holy month of Ramadan.

Commanders are hearing that Taliban leaders might leave their fighters in the country to try to regain lost ground during the Islamic holy period which begins Monday, rather than crossing the border to Pakistan, said Adm. Mike Mullen, the Joint Chiefs chairman.

Mullen, who visited U.S. outposts along Afghanistan’s eastern border on Sunday, also said U.S. troops are making progress in their renewed campaign against Haqqani network insurgents in havens in Pakistan. And he issued another warning that Islamabad must step up its efforts to root out those militants.

Speaking to reporters traveling with him in Afghanistan, Mullen said Marine Gen. John Allen, who has just taken over as top U.S. commander here, needs time to evaluate the combat, training and other requirements before presenting a detailed withdrawal plan.

Mullen’s comments for the first time laid out a deadline for Allen to structure the planned withdrawal of 10,000 U.S. troops by the end of the year, as announced by President Barack Obama.

“The next month will be very telling,” said Mullen, noting that often the Taliban leaders will travel back to Pakistan for Ramadan. It’s unclear at this point what they will do, or if there will be any decline in the fighting.

U.S. military leaders have said they plan to shift resources and perhaps some troops to the eastern border in the coming months, and Mullen said commanders he met with along the eastern border said the strategy is working.

“The overall goal has been to make it much more difficult for the Haqqani network to penetrate directly in what has previously been called this jet stream between Pakistan, right through Khost into Kabul, and it is more difficult,” Mullen said during a news conference shortly after he returned from the volatile border. “That will clearly continue to be the case.”

At the same time, however, a senior NATO military official said coalition forces will likely never eliminate the havens. The official, who spoke on condition of anonymity to discuss sensitive issues, said that instead the goal is to intensify U.S. efforts while building the Afghan forces so that they can take over the battle for their own security there.

U.S. officials have been pressing Pakistan to go after Haqqani militants and other fighters who routinely launch attacks into Afghanistan from Pakistan. But relations with Islamabad have frayed, particularly after the U.S. raid in May that killed Osama bin Laden. In recent weeks, the Obama administration moved to delay $800 million in aid to Pakistan, to put further pressure on the government, which has been reluctant to push into North Waziristan and go after the Haqqani network.

Acknowledging the ongoing frustration with Islamabad, Mullen said Sunday that the U.S. will continue to push for action, “but I would be hard pressed to tell you when it’s going to happen.”

On Ramadan, one Western official said that while Taliban leaders have pushed for an increase in violence through the holy month, information suggests there will be some spikes but that they don’t have the ability to carry off a sustained surge. The official, speaking on condition of anonymity because of the sensitivity of the issue, said some leaders and fighters had already left Afghanistan to cross the border into Pakistan, but it is too soon to tell how many may stay.

Mullen, who arrived Friday in Afghanistan, met Saturday with commanders in southern Afghanistan.

He said that so far commanders are saying they are seeing some signs of improved security, but his comments came amid a series of spectacular deadly attacks across the south, including a bombing Sunday outside the main gate of the police headquarters in the southern Afghan city of Lashkar Gah. The suicide bomber killed at least 11 people in a city where Afghans had only recently taken control of security.

That attack comes on the heels of bombings in the southern province of Uruzgan that killed at least 19 people, and the assassination of Kandahar’s mayor.

The mayor was the third southern Afghan leader to be killed in the last three weeks.

There are nearly 100,000 U.S. troops in Afghanistan. Under Obama’s troop withdrawal plan, 10,000 U.S. troops will leave Afghanistan by the end of the year, and another 23,000 by the end of next summer.

A key to the withdrawal is the ongoing effort to train Afghan forces so they can take control of their own security. Mullen said that while training remains a top priority, and commanders would like to accelerate it, it’s not clear how possible that will be over the coming months.