America made a concession in the row over torture of terror suspects yesterday, promising that its personnel would not abuse detainees at home or abroad.

In a shift flagged by her diplomats as a major policy change, Secretary of State Rice said America would meet its international treaty obligations worldwide.

Previously, the Americans had blurred the issue, refusing to rule out inhumane treatment short of torture by intelligence officers overseas. That fuelled widespread suspicion that the CIA was mistreating prisoners to extract information helpful in the war on terrorism.

The reverse came after criticism which had made Ms. Rice’s current tour of Europe increasingly awkward.

Prime Minister Blair was at the centre of a growing controversy over “rendition” after he told lawmakers he was unaware of reports that almost 400 flights by suspected CIA planes had passed through British airports.

Downing Street insisted yesterday that Britain was not party to the details of the American policy. “We do not believe we are involved in this story,” the prime minister’s official spokesman said.

Speaking in Ukraine, Ms. Rice pledged America would follow its obligations under the 1987 U.N. Convention Against Torture.

“Those obligations extend to U.S. personnel wherever they are, whether they are in the United States or outside of the United States,” she said.

But officials traveling with Ms. Rice emphasized the change had not been triggered by European attacks.

The past few weeks have been dominated by revelations that the CIA had been running secret “black sites” in Eastern Europe for the interrogation of the most senior Al Qaeda captives. Top detainees, including lieutenants and planners who once worked for Osama bin Laden, were recently transferred to a new site in North Africa, it has been reported.

The timing of Ms. Rice’s words gave the appearance that Washington recognized the controversy was worsening its already damaged reputation among close allies.

In the House of Commons, Mr. Blair appeared to defend cooperation with America over the transfer of terrorism suspects but insisted torture could never be justified.

Yet it remains highly unlikely that the Americans will accept demands by some Europeans for the suspects to be offered full legal rights and trials.

Many Western counterterrorism officers would view that as extremely risky, opening the possibility for detainees to be acquitted and released.