Iran on Sunday repeated its offer to help the United States in finding an ex-FBI agent who went missing while on a trip to the Islamic republic to probe cigarette counterfeiting in the region. On Friday the United States, arch-foe of Iran, asked again for Tehran's help in finding Robert Levinson who disappeared six years ago from the Gulf island of Kish. "We have said many times that we do not have any information in this regard," Foreign Minister Ali Akbar Salehi was quoted as saying by the ISNA and IRNA news agencies.

(Adds comments from the White House) By Sarah N. Lynch WASHINGTON, March 8 (Reuters) - U.S. Secretary of State John Kerry on Friday met with the family of a former FBI agent who disappeared in Iran in 2007, and urged anyone who may have information about his whereabouts to come forward.

Sanctions on Iran over its contested nuclear programme are biting but need to be strengthened further, French President Francois Hollande and his Israeli counterpart Shimon Peres said on Friday. Western powers suspect Iran's nuclear programme to be a cover for building an atomic weapons capability, a charge which Tehran strongly denies. "I have said how much we want the sanctions to be beefed up, which are already efficient," Hollande said after meeting Peres.

World powers gave no ground to Iran at negotiations in Almaty last month and only recognised some of Tehran's rights, the Islamic republic's supreme leader said on Thursday. "At the (February 26-27) meeting, the Westerners did nothing of importance that could be termed a gesture," Ayatollah Ali Khamenei said in speech reported on his website. "All they did was recognise a part of the rights of Iran" to develop nuclear energy, he said, adding that the next meeting, due to take place on April 5-6 in the Kazakh city, would "help gauge the sincerity" of world powers.