Iranian deputy nuclear negotiator Ali Bagheri said the first home-made nuclear fuel rods were to be placed into Tehran research reactor on Wednesday, the semi-official ISNA news agency reported on Wednesday.

"We have started enriching uranium to 20 percent to build nuclear fuel rods since Western countries are reluctant to provide us with assistance," Bagheri was quoted as saying.

Iran's presidential website announced on Tuesday that Iranian President Mahmoud Ahmadinejad would unveil "some nuclear achievements" on Wednesday.

"In the presence of the president, some new and worthwhile achievements of the country's nuclear scientists in the field of atomic energy will be unveiled" on Wednesday, the announcement said.