The Obama administration reportedly has developed a plan to begin transferring security in some areas of Afghanistan to the country's forces over the next 18 to 24 months, with a goal of ending U.S. combat missions there by 2014.

The four-year plan to wind down U.S. and allied fighting in Afghanistan will be presented to a NATO summit meeting in Lisbon later this week and "reflects the most concrete vision for transition in Afghanistan assembled by civilian and military officials since President Obama took office last year," The New York Times reported late Sunday.

In many respects, the concept follows the precedent set in Iraq, where a similar troop surge and strategy shift under President George W. Bush in 2007 enabled U.S.-led coalition forces to eventually hand over security duties to the Iraqis region by region, the paper said. Last summer, President Obama was able to withdraw two-thirds of U.S. forces from Iraq and declare the U.S. combat mission there over.

"Iraq is a pretty decent blueprint for how to transition in Afghanistan," the Times quoted an unnamed U.S. official as saying. "But the key will be constructing an Afghan force that is truly capable of taking the lead."

The U.S. is already assessing areas of Afghanistan that could be safely handed over to local security forces, and is poised to have them identified as early as later this year, the paper cited officials as saying.

Word of the plan came as the commander of U.S. and NATO forces in Afghanistan warned Afghan officials Sunday that President Hamid Karzai's recent public criticism of U.S. strategy is seriously undermining the war effort, The Washington Post reported Monday.

Gen. David Petraeus expressed "astonishment and disappointment" over Karzai's call to "reduce military operations" and end U.S. Special Operations raids in southern Afghanistan, the Post reported, citing unnamed Afghan and U.S. officials.

In a meeting with the official leading Afghanistan transition planning, Petraeus made what officials described as "hypothetical" references to an inability to continue U.S. operations in the face of Karzai's remarks, the Post said.

The Afghan president had said in an interview published Sunday that the presence of about 100,000 U.S. troops and especially "terrible" night raids conducted by U.S. forces on Afghan homes, inflamed the emotions of Afghans, leading young men to join the insurgency.

"The time has come to reduce military operations," Karzai said. "The time has come to reduce the presence of, you know, boots in Afghanistan ... to reduce the intrusiveness into the daily Afghan life."

Officials denied to the Post reports on Sunday that Petraeus had threatened to resign. But "for [Karzai] to go this way, and at that particular stage, is really undermining [Petraeus's] endeavors," one foreign diplomat in Kabul reportedly said. "Not only his personally, but the international community."

Karzai's remarks surprised a U.S. lawmaker in Washington who visited Karzai last week.

"I'm just stunned," U.S. Sen. Lindsey Graham, a Republican from South Carolina, told ABC's "This Week" on Sunday. "To take the night raids off the table would be a disaster."

Graham said he met Karzai as part of a congressional delegation that visited Afghanistan last week and the president never raised the issue of night raids.

Graham said Petraeus must be allowed to continue with his counterinsurgency strategy. "We own the night militarily, and are making a huge impact on the Taliban, the insurgency as a whole," he said.

A senior official with the coalition said the NATO raids, which have increased six-fold in the past 18 months, are conducted in full partnership with Afghan troops.

The official, who spoke on condition of anonymity to discuss Karzai's remarks, said that the coalition shares Karzai's concerns about the operations. But he said that precision operations against high-value insurgents and their networks remained a key component of NATO's comprehensive civilian-military counterinsurgency operations.

Separately, NATO said Monday that another two service members died in an insurgent attack in eastern Afghanistan the previous day, raising the toll of those killed in the single incident to five. The deaths bring to 33 the number of coalition service members who have died in Afghanistan so far this month. In another attack, an insurgent rocket sparked a huge blaze inside an American base.

The international military coalition did not provide details on Sunday's attack or the nationalities of the service members. Though a number of nations have troops in the east, the majority of the forces are American.

The deadly strike came a day after Taliban fighters stormed a NATO base in eastern Afghanistan, showing the insurgents' determination to stage attacks despite a surge of U.S. troops and firepower.

In eastern Kunar province on Monday, an insurgent rocket struck inside a U.S. base near the provincial capital of Asadabad, sparking a blaze that destroyed six armored vehicles and an ambulance, NATO and Afghan officials said.

Associated Press Television News video showed plumes of black smoke rising from inside Camp Wright through much of the morning, with flames shooting up into the air. Provincial police chief Khalilullah Zaiyi said Afghan firefighters were dispatched to help quell the blaze.

Taliban spokesman Zabiullah Mujahid claimed responsibility for the attack.

The base came under attack from gunfire and rockets early in the morning and one rocket hit a fuel container, starting the fire, NATO said. There were no coalition injuries and the fire was contained by late morning. The six armored vehicles destroyed were Mine Resistant Ambush-Protected vehicles known as MRAPS, which can cost as much as $1 million each.

The Associated Press, NewsCore and Reuters contributed to this report.