Iran's nuclear negotiator Said Jalili sent a protest to European Union foreign policy chief Javier Solana Monday over the West's attitude to his country's atomic programme, a senior Iranian official said.
"In the letter, Mr Jalili complains of the attitude of the West and says their approach has harmed the constructive process of negotiations between the two parties," the official told AFP, declining to be named.
"In the course of negotiations, pressure instead of reason will not be a resolution," the official news agency IRNA cited the two-page letter as saying.
The office of Iran's Supreme National Security Council said the letter was delivered to Solana Monday by the Islamic republic's ambassador to Brussels, Ali Asghar Khaji.
Copies of the letter are due to go to the foreign ministers of the five U.N. Security Council permanent members - the U.K., China, France, Russia and United States - plus Germany.
Iran says it has a right to enrich uranium to make nuclear fuel as a signatory to the nuclear Non-Proliferation Treaty and denies allegations of seeking atomic weapons.