Iran's supreme leader said on Thursday the United States was deeply hated in the Middle East and told US President Barack Obama that "beautiful" speeches alone would not improve its image in the Muslim world.
Speaking on the same day Obama was due to give a major speech to the Islamic world in Cairo, Ayatollah Ali Khamenei said the hatred felt toward America could not be changed with "slogans" but that different US action was needed.
In a break from the policies of his predecessor George W. Bush, Obama is offering improved ties with the Islamic Republic if it "unclenches its fist". Iranian leaders say they want to see a real shift in the policies of their old foe.
"The nations of this part of the world ... deeply hate America because during many years they have seen violence, military interference, rights violations, discrimination ... from America," Khamenei said in a televised speech.
"Even if they give sweet and beautiful talks to the Muslim nation ... that will not create a change," said Khamenei, Iran's most powerful figure with the final say on all matters of state. "Nothing will change with speeches and slogans."
He spoke at an event in Tehran to mark the 20th anniversary of the death of his predecessor, Ayatollah Ruhollah Khomeini, the founder of the Islamic Republic.
He also called Israel, which Iran does not recognize, a "cancerous tumor in the heart" of the Muslim world.
Obama's speech later on Thursday is aimed at more than 1 billion Muslims across the world but choosing Cairo underscores his focus on the Middle East, where he faces some of his biggest foreign policy challenges.
West speaking 'softly'
Obama wants to build a coalition of Muslim governments that will back his efforts to revive stalled Middle East peace talks and help the United States curb Iran's nuclear program, which Tehran says is peaceful but the West says is to build bombs.
"If you (Muslims) see that the Western world is talking more softly to you it is the result of public awareness and resistance in the Islamic world," Khamenei said.
Israel, widely believed to be the Middle East's only nuclear power, has repeatedly described Iran's nuclear activities as a threat to its existence and neither it nor Washington have ruled out military action if diplomacy fails to resolve the row.
Khamenei accused the United States, which Iranian leaders often refer to as the "Great Satan" guilty of "global arrogance", of lying about Tehran's nuclear ambitions.
"The Iranian nation has repeatedly announced that it does not want nuclear weapons ... keeping nuclear arms would create a big danger and trouble and even if they pay us we do not want it," he said.
Khamenei said the United States had occupied two Muslim countries, Iraq and Afghanistan, under the pretext of fighting terrorism.
"The terrorists kill one, two or ten people ... but you kill 100 or 150 people," he said, referring to a rising civilian death toll as foreign and Afghan troops battle Taliban insurgents.