TEHRAN: Iran's Supreme Leader Ayatollah Ali Khamenei said yesterday US President Barack Obama's offer of better ties was just a "slogan", but pledged Tehran would respond to any real policy shift by Washington.

Speaking a day after Obama's videotaped overture marking Iranian New Year, Iran's most powerful figure criticised US actions towards Tehran since its 1979 Islamic revolution and said he did not see any change in practice from the new administration so far.

But Khamenei added: "You change, our behaviour will change."

Indicating areas where Iran wants a different US approach, he said the US was "hated in the world" and should stop interfering in other countries' internal affairs.

He also spoke of "oppressive sanctions" imposed on the Islamic republic, Iranian assets frozen in the US and Washington's backing of Israel.

Meanwhile, Russian Foreign Minister Sergei Lavrov said there was no proof that Iran is trying to develop a nuclear weapon and urged the West to respect and reach out to the Islamic republic.