TEHRAN, June 15 (RIA Novosti) - Iran's Supreme Leader Ayatollah Ali Khamenei said Thursday Iran would not back down over its nuclear program and would continue with scientific research.

"Iran will not retreat under pressure and its main priority is to carry on with scientific research [in nuclear sector]," Khamenei told an Iranian television channel.

Iran's nuclear programs have been a source of major controversy since the beginning of the year, as many countries suspect the Islamic Republic of pursuing a covert weapons program under the pretext of civilian research, despite its claims to the contrary.

"The development of civilian-use nuclear technologies by young Iranian scientists is a historic step, and research in nuclear sector should be carried on," Khamenei said.