Supreme Leader Ayatollah Ali Khamenei said Iran would not step back from its nuclear rights and his negotiating team has been setting limits for talks over the country's nuclear program, to resume in Geneva later on Wednesday.

"We do insist that we will not step back one iota from our rights," Khamenei said in a speech in Teheran, broadcast live on Iran's Press TV with English translation.

The most powerful figure in Iran continued: "We do not intervene in the details of these talks. There are certain red lines and limits. These have to be observed. They are instructed to abide by those limits."

In a likely reference to United Nations, US and European Union sanctions imposed over Iran's nuclear activities, Khamenei said: "They intend to ratchet up the pressure on Iran. Iranians will succumb to no one under pressure.

"We will slap aggressors in the face in such a way they will never forget it," he added, without referring to any specific country.

Reuters