The US will reply "to the best of our ability" to EU questions about reports of secret US-run prisons for terrorism suspects in Europe, the State Department said.
Britain, which holds the revolving presidency of the EU, sent a two-paragraph letter to Washington on Tuesday with the request. It came after weeks of increasing concern in Europe over reports that the CIA has detained and interrogated terrorism prisoners in Soviet-era compounds in Eastern Europe.
US State Department spokesman Sean McCormack would not answer questions about whether the sites exist or whether the CIA used European airports and airspace to transport suspects.
He would not say whether the US response to the EU would provide definitive answers, nor whether the US response would be made public. "We will ... endeavour to respond to this letter to the best of our ability, in a timely and forthright manner," he said. Mr McCormack set no deadline for a reply.
Next week, US Secretary of State Condoleezza Rice
The Washington Post first reported on the alleged prison network on November 2nd.
It would be illegal for the US government to hold prisoners in isolation and difficult conditions in secret prisons in the US. It long has been assumed that the CIA operates overseas sites to get around US law and to keep terrorism suspects out of the jurisdiction of American courts.
Concerns about alleged CIA activities in Europe have led to investigations in a half-dozen countries.
The CIA has declined to comment on the investigations; the White House and State Department have not confirmed any of the allegations.
Neither the US nor Britain has released the text of the letter. Other nations have made independent attempts to ask the US if the allegations are true; Mr McCormack said there have been no replies yet.
will be in Europe, including Romania, one of the nations identified by Human Rights Watch as a likely site of a secret detention camp.