
The Prime Minister has expressed "disappointment" after revelations that US "rendition" flights had twice landed on British soil.
Gordon Brown said he was determined to put safeguards in place so that similar incidents could not happen in future.
Foreign Secretary David Miliband said in a Commons statement that on two occasions in 2002, US flights carrying terrorist suspects stopped to refuel at the airbase on the British Indian Ocean territory of Diego Garcia.
He told MPs that US officials informed the UK last week of the flights, which took place contrary to earlier assurances given by the US.
Speaking in Brussels, Mr Brown said: "The US has expressed regret that it did not admit at the time to these renditions through Diego Garcia.
"We have got to assure ourselves that these procedures will never happen again."
Mr Miliband apologised to Parliament on behalf of the Government for providing inaccurate information.
He said his concern about the case was shared by US secretary of state Condoleezza Rice.
"We both agree that the mistakes made in these two cases are not acceptable and she shares my deep regret that this information has only just come to light," he said.
Mr Miliband told the Commons the cases had not come to light earlier because of an "error" in an earlier US records search.
He said that in each of the two cases, the aircraft involved had been carrying a single detainee - neither of them British.
One has since been released, but the other is still being held at Guantanamo Bay.
Mr Miliband said the Americans have given an assurance that no detainees were held on Diego Garcia and that they had no record of any other rendition through Diego Garcia or any other UK territory.
Nevertheless, he said he has now ordered officials to draw up a list of all flights about which concerns had been expressed regarding the use of UK territory.
He said it would be presented to the Americans with a view to seeking their "specific assurance" that none of the flights had been used for rendition purposes.
Shadow foreign secretary William Hague said the Government statement would cause "widespread concern" given the "categoric" nature of previous assurances.
"The delay in releasing this information and the evident absence of a request in these cases are bound to undermine public trust, to some extent, in the arrangements which we have with the United States," he said.
"The efforts of the United States, our most important ally, to fight international terror are essential to the security not only of America but of Britain and many other nations.
"But allegations that rendition has led to the torture of terrorist suspects have been used to undermine the moral standing of the US and its allies.
"If such torture has occurred, it is fundamentally wrong."
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