The Taliban broke off contacts over peace talks with Washington on Thursday and the Afghan president demanded US troops leave village outposts, just days after an American soldier massacred 16 villagers.

Hamid Karzai also called for a transition of the nation's security from NATO control to the Afghan government in 2013 rather than the previous deadline of 2014, after meeting visiting US Defence Secretary Leon Panetta.

That plan had been floated by Panetta ahead of a NATO meeting in Brussels last month, but the US-led coalition insists that it will only withdraw its combat troops by the end of 2014.

The announcements from the Islamist militia fighting US troops for 10 years and by Karzai, Washington's key ally in Kabul, came hard on the heels of the shooting spree by a US soldier, who has been detained and flown out of the country.

The fallout overshadowed Panetta's two-day visit to Afghanistan, which was planned ahead of the shooting and was aimed at calming relations already hurt by last month's burning of Korans at a US base.

The Taliban made no mention of the killings as it announced the suspension of contacts with US officials in Qatar over a prisoner swap -- talks that had built up hopes of a political solution before US troops leave.

"It was due to their alternating and ever-changing position that the Islamic Emirate was compelled to suspend all dialogue with the Americans," the Taliban said on their website.

US officials declined to comment on why the Taliban had suspended contacts.

The rapid developments came after what US Secretary of State Hillary Clinton called "a difficult and complex few weeks in Afghanistan".

"We're ready to take over all security responsibilities now," Karzai's spokesman Aimal Faizi quoted the president as telling Panetta. "We'd prefer that the process be completed in 2013, not 2014."

Karzai then told Panetta that US-led international forces should "be withdrawn from villages and relocated in their bases", his office said in a statement, without specifying a timeline.

It was not immediately clear how many American bases may be affected by Karzai's demand, as the United States previously disbanded a number of outposts in a bid to concentrate on securing major towns from Taliban influence.

US defence officials sought to play down Karzai's calls on the outposts and said Kabul had not requested any change in an agreed timetable for a gradual troop drawdown.

A US official accompanying Panetta, who arrived in Abu Dhabi after his visit to Afghanistan, told reporters Kabul had agreed with NATO on a schedule for security transition through 2014 and that had not changed.

Panetta's spokesman George Little said the Pentagon chief and Karzai had a "very positive" meeting and that the "issue of villages" came up but in accordance with previously agreed plans.

NATO meanwhile vowed to stick to its plan to finish handing Afghans control of security nationwide by the end of 2014.

Panetta earlier told reporters after his Karzai talks that he was "confident" both sides could work out a treaty allowing a US military presence in the country beyond 2014.

The defence chief said he was optimistic that both sides would reach an agreement on controversial night raids -- a major issue blocking the treaty -- ahead of a NATO summit in Chicago in May.

Karzai objects to the raids on the grounds that they violate the sanctity of Afghan families in their own homes and that they are responsible for many civilian deaths -- a claim the US disputes.

The treaty being negotiated is expected to cover Afghan-US relations beyond 2014, with the US keen to maintain a foothold in a country neighbouring Iran and to help prevent it from once again becoming a haven for Al-Qaeda.

Analysts fear Sunday's shootings could complicate talks on a possible long-term US troop presence, as the government has so far refused to grant them legal immunity -- the same issue that scuppered a US strategic pact with Iraq.

Panetta said he promised Karzai that the gunman would be brought to justice and that the Pentagon would look at what circumstances may have caused the incident -- including the possible effect of combat stress.

But his visit was also overshadowed by an unprecedented security breach during his arrival in Afghanistan Wednesday when an Afghan interpreter tried to ram a truck into US Marines waiting to greet the Pentagon chief at Camp Bastion.

Panetta downplayed the attack, telling reporters: "I have absolutely no reason to believe that this was directed at me."

But the incident is likely to heighten concerns about a surge in attacks on Western troops carried out by the Afghan allies they are training to take over responsibility for security.

Security breach overshadows Karzai-Panetta talks
Kabul (AFP) March 15, 2012 - An Afghan died Thursday after trying to ram a truck into US Marines waiting to greet the Pentagon chief in an unprecedented security breach overshadowing what was billed as a fence-mending visit.

The still puzzling incident, which American officials took 10 hours to confirm, took place as Leon Panetta flew into the high security Camp Bastion base in southern Afghanistan on Wednesday ahead of talks with Afghan leaders.

Panetta sought to downplay the incident, following talks with President Hamid Karzai billed as a chance to calm anger over a US soldier allegedly killing 16 villagers on Sunday and copies of the Koran being burnt last month.

"I have absolutely no reason to believe that this was directed at me," he told a press conference, but added: "This is a war area" and "we're going to get these kind of incidents".

Separate bomb attacks killed at least 15 Afghans in the south during his two-day visit -- eight civilians in Helmand and a policeman in Kandahar on Wednesday and six civilians in a roadside bomb in Uruzgan on Thursday.

Military officials have dripped out confused details of the attempted airport attack, claiming first that there was no link to Panetta's arrival and then confirming that the target was indeed his US Marine welcoming committee.

The incident is likely to heighten concerns about a surge in attacks on Western troops carried out by Afghans being trained to take over security in the war-torn country when US and NATO allies pull out in 2014.

According to US officials, an Afghan interpreter hijacked a pick-up truck from a soldier and drove it at a group of US Marines on the airfield tarmac, before it crashed and burst into flames.

The Marines he tried to run over "were assembled to meet the secretary of defence's plane", a military official told reporters on condition of anonymity.

General Mike Scaparrotti said earlier that he believed the Afghan "had the intent to harm" but sought to downplay any threat to Panetta.

There is "no way you can identify one aircraft from the other," he said.

The Afghan, who was engulfed in flames after crashing the vehicle, had a container of fuel in the car and Scaparrotti said he died early Thursday, but that there had been no explosives in the vehicle or strapped to the man.

A British soldier was injured "in the course of the theft" of the vehicle, the military official said, without giving details.

In a later twist, a senior defence official said a military dog helped in the "pursuit" and "restraint" of the Afghan and suffered minor burns.

Panetta's visit had been billed as an opportunity to smooth over relations with Afghan leaders, which took a severe knock when a US soldier allegedly massacred 16 villagers on Sunday and copies of the Koran were burnt last month.

Most of those killed were women and children in two villages in southern Kandahar province, a key Taliban stronghold, in the worst single such incident since the 2001 US-led invasion.

The suspect, a US Army sergeant who served three tours in Iraq, has been flown to Kuwait, in a first step towards being charged and put on trial outside Afghanistan, defying demands by Afghan leaders for a public trial at home.

Scaparrotti, deputy commander of US forces, said the transfer was carried out to ensure the suspect received fair legal treatment and expected that the alleged gunman would soon be formally charged.

"In serious incidents, we move individuals to a location that we can provide both proper pre-trial confinement (and) access to legal services," he said.

On Thursday, about 1,000 Afghans took to the streets in Zabul province, which neighbours Kandahar, to denounce the shooting and demand a public trial for the culprit.

Analysts believe the shootings could complicate already difficult talks with Kabul on a possible US troop presence after 2014, as the government has so far refused to grant legal immunity to American troops -- the same issue that scuppered a US strategic pact with Iraq.

Panetta on Wednesday insisted that "troubling" events should not force a change in NATO's war strategy and said that progress was being made in the 10-year war against the Taliban.

In Washington, President Barack Obama said there were no plans for "sudden" changes to a scheduled timetable for troop withdrawal and said the United States would stick to plans for Afghan forces to take over security in 2014.