Iran has prepared a high-level delegation to hold talks with the US, but the Bush administration, which insists negotiations be limited to the subject of Iraq, is resisting a wide-ranging agenda, Iranian politicians have told the Financial Times.

A senior Iranian official, Mohammad Nahavandian, has flown to Washington to "lobby" over the issue, according to a top Iranian adviser outside the US. However, the Iranian mission to the United Nations said he was in Washington on private business.