Iran's Foreign Minister Kamal Kharrazi said Tehran was willing to resume dialogue with the United States, provided the talks were based on mutual respect, state television reported on Thursday.
Kharrazi added that Iran's recent negotiations with European countries over its nuclear programme, which culminated in Iran agreeing to snap inspections of nuclear facilities, was an example to Washington of how outstanding problems can be solved.
But Supreme Leader Ayatollah Ali Khamenei, who has the last word on all state matters, said in a televised speech that deep-rooted problems between the two arch-foes remained and accused Washington of trying to exploit Iran's recent earthquake for political gain.
Speculation has mounted in recent days that the two countries may be edging towards some kind of rapprochement, after US officials spoke of a willingness to resume a limited dialogue on specific issues and Washington sent humanitarian aid to victims of the devastating December 26 earthquake in Bam.
"Iran is ready to negotiate with all countries and America is no exception," Kharrazi told state television. "If it (Washington) adopts a new approach to Iran and is ready to interact with us based on mutual respect and the principle of equality, the atmosphere will change remarkably."
Washington cut ties with Iran shortly after the 1979 Islamic revolution and has labelled it part of an "axis of evil."
Khamenei's comments reflected the long-standing split between Iran's reformers and hard-liners on how to deal with the superpower the conservatives call the "Great Satan"."
In his speech, broadcast on state television, Khamenei said Washington had used the Bam quake as "an opportunity to pursue their political goals."
"They hide their iron fist in a silk glove," he said.