Petraeus will also want to confirm that the British government will not  cut its military spend on Afghanistan [EPA]

Britain's prime minister is meeting the top US commander in Afghanistan as new details emerge of the rescue operation that may have killed an aid worker in the eastern Kunar province.

David Cameron and General David Petraeus are holding taks on the issue in London, the British capital.

Linda Norgrove, a 36-year-old Briton kidnapped in Afghanistan, was initially believed to have been killed by a vest of explosives detonated by her captors.

But it later emerged that she may have been killed by a grenade thrown by US troops, with new details suggesting that the US special forces soldier believed to be responsible failed to see that she had broken away from the kidnappers.

Britain's Guardian newspaper reported that Norgrove was lying in a foetal position to keep safe when a US grenade was thrown during an attempt to rescue her on Friday night.

A US-UK investigation is under way to establish what happened.

Details 'still unclear'

Tim Friend, Al Jazeera's correspondent in London, said Thursday's meeting was "likely to be a tense one".

"Both men agree they've handled this in the best way they could but this does not distract from the tragedy," he said. 

"It's become increasingly clear that US forces could have been responsible for Linda Norgrove's death.

"For the most part, people accept that in the chaos of conflict occassionaly tragedies will occur, and Linda Norgrove's family have said that they are glad that the US is being open about this so far and are sharing what they know."

The Guardian reported that the US soldier could face disciplinary action, citing sources in London and Kabul.

It said the soldier failed to inform his commanding officers that he had thrown the explosive until long after the event.

Cameron said on Tuesday that the circumstances surrounding the aid worker's death were still "unclear".

"The responsibility for Linda's death lies with those cowardly, ruthless people who took her hostage in the first place," he said.

Norgrove was working for Development Alternatives Inc, a US organisation, in Kunar when she was seized by fighters in Kunar province on September 26.

Petraeus is also be talking to Cameron about Britain's defence review to be announced next week.

He wants reassurance about the impact of cuts at the defence ministry on the UK's role in Afghanistan.

There have been concerns in Washington that any scaling back of British defence capabilities may have implications for the UK's ability to support the US in future deployments.

Source: Al Jazeera and agencies