Britain is hoping to persuade the US to rectify its "unacceptable" refusal to send experts to give evidence at coroner's inquests into British troop deaths in Iraq, a senior minister said.
Constitutional Affairs Minister Harriet Harman said she was seeking a meeting with senior US officials to persuade them to provide live testimony to help families understand better how their loved ones died.
The issue has come to the fore following repeated remarks by a coroner about the US military's unwillingness to cooperate with inquests in the UK.
The inquests are required under British law when a UK citizen dies abroad and the body is repatriated.
Andrew Walker last month publicly blamed US Marines for the unlawful killing of a British journalist, his Lebanese interpreter and French cameraman in Iraq in 2003 and would try to ensure they were prosecuted.
Terry Lloyd, Hussein Osman and Fred Nerac were shot near the southern city of Basra two days into the US-led invasion, but none of those involved in the shooting gave evidence.
Walker reiterated his complaint at the inquest into the deaths on the same day of two British Royal Air Force personnel who were shot down by a US Patriot missile as they approached an air base in Kuwait following a sortie in Iraq.
Harman told ITV1 television in an interview to be broadcast yesterday that to deny grieving families the chance to know what happened was unacceptable.
"If our service people have died in Iraq, the very least we can do is to make sure there is a proper inquest, so their families can understand the truth of the situation of how their loved ones died," she said.
"We need those American service people and experts to be in the coroner's court in order to give an account of the situation," she said.
"When they don't come that's not acceptable and we are prepared to say that's not acceptable," she said.
Britain, which still has about 7,000 troops mainly in southern Iraq, has suffered 121 military fatalities since the start of the war.