TEHRAN, (Reuters) – Iran told Britain not to cross any “red lines” when preparing incentives for the Islamic Republic aimed at ending a row with the West over Tehran’s nuclear programme, the Iranian foreign minister said on Saturday.

World powers met in London on Friday and said they would offer new incentives to encourage Iran to halt nuclear work which the West fears is aimed at building atomic bombs.

Iran refused the last such offer made in 2006 and officials have in the past described a demand that Iran suspend its uranium enrichment programme as a “red line”. They say it is Iran’s right to carry out such work and say the aim is peaceful.

Iranian Foreign Minister Manouchehr said he met his British counterpart, David Miliband, in Kuwait recently. Britain and Iran attended a multilateral meeting there on Iraq last month.

Miliband had said world powers would meet in May and planned to “write a letter” to Tehran, Mottaki said. “I told him that ‘You have used a word, and I think it is a forbidden word … Don’t pass those red lines. Be careful about that’,” Mottaki said without saying what those “red lines” were.

Mottaki was speaking at a news conference with a visiting Yemeni minister broadcast and translated by Iran’s Press TV. “We have not received any letter in this connection,” Mottaki was quoted by ISNA news agency as saying when asked about a new offer by the six world powers, comprising the United States, Britain, France, Germany, Russia and China.

Iran, the world’s fourth largest oil producer, says it wants only to make fuel for power plants. The enrichment process, if desired, can also be used to make material for bombs.

The U.N. Security Council has imposed sanctions on Iran for failing to heed the demand to suspend enrichment work.

Iranian state media were dismissive about the new package. “What has been obtained about the new proposed package from the 5+1 meeting in London is nothing beyond the group’s previous repetitious proposal,” state TV reported.

The incentives offered to Iran in 2006 included civil nuclear cooperation and wider trade in civil aircraft, energy, high technology and agriculture, if Tehran suspended uranium enrichment and negotiated with the six world powers.

A European diplomat said the heart of the previous offer — helping Iran develop civil nuclear power, including with state-of-the-art technology — remained. Miliband said details would be revealed by the six only to Iran’s government.

Iran discussed its own package of proposals with a visiting Russian official this week about how to resolve the nuclear row. It has not given details about those plans.