Britain, Washington's staunchest ally in the war in Iraq, admitted on today to differences with its partner over how to tackle the nuclear ambitions of Iran.
While the United States reacted quickly and harshly to an International Atomic Energy Agency (IAEA) report which said Tehran had dabbled in activities possibly linked to atom bomb-making, British Foreign Secretary Jack Straw unusually broke ranks today to strike a milder note.
"We should be reacting calmly to the latest report from the International Atomic Energy Agency," he told BBC Radio. "This report, which certainly is very worrying in terms of what it discloses, also shows a pretty high level of cooperation."
The nuclear safety agency's report this week said although no evidence had so far been found of a bomb programme in Iran, Tehran had experimented with possibly linked activities like plutonium production and uranium enrichment.
The report prompted US Secretary of State Colin Powell to accuse "hidebound clerics" in Tehran of dragging Islam into "the political gutter".
Straw will meet Powell for talks in Washington later in the day. The United States wants the IAEA board to pass a resolution to report Iran to the UN Security Council, a move which could lead to sanctions against Tehran.
But Britain may resist, along with France and Germany.
The three have tried to engage with Iran, to the dismay ofWashington which has long taken a tougher line. Last month theEuropean trio secured Iranian agreement to snap inspections ofits nuclear sites and a freeze of uranium enrichment.
Speaking on BBC Radio, Straw, who has made building tieswith Tehran a cornerstone of his diplomatic agenda, was carefulto respect Iran's heritage.
"We want to see a process by which Iran comes fully into thedemocratic modern fold while being able to show full respect toits Islamic roots and the fact that it is an Islamic republic,"he said, going on to admit differences with Washington.
"Because of the history between Iran and the United States,the issue...is felt more sensitively than it is in Europe," hesaid. "We have different analyses but we share a commonobjective."