Iran replied to demands by world powers that it end its suspected nuclear weapons program.
The U.S. State Department confirmed the receipt of Iran’s letter on Monday but would not reveal its contents.
Last month, the five permanent veto-wielding powers on the United Nations Security Council – Russia, the United States, France, Britain and China – as well as Germany reaffirmed existing sanctions aimed at stopping Iran from enriching uranium.
Within the grouping known as “P5 Plus One,” the United States, France, Britain and Germany had hoped to expand sanctions for a fourth time since last year, but Russia and China resisted.
The United States in the meantime chided Western energy companies for participating in a conference on natural gas production over the weekend in Tehran. Media reports named participating Western companies as Shell from the Netherlands, BP from Britain, Total from France and OMV from Austria.
“Now is not the time to be discussing with Iran investments in its oil and gas industry, given its status in the international community regarding its behaviors which are clearly outside the norm and have been judged by the Security Council to be outside acceptable international behavior,” State Department spokesman Sean McCormack said last week.
The Bush administration separately allowed a U.S. nonprofit group, the American-Iranian Council, to open an office in Tehran in order to “increase people-to-people contacts between the people of Iran and the people of the United States in order to expand mutual understanding,” according to the State Department.