An Iranian negotiator warned Sunday that this month's talks in Moscow over Iran's nuclear program could stall because of faulty preparation.
Ali Bagheri, Iran's No. 2 nuclear negotiator, said advance talks were agreed on to clarify the agenda for the Moscow round, set for June 18-19.
The official IRNA news agency said Bagheri made the complaint in a letter to senior EU official Helga Schmid on Sunday.
Concerned that Iran might be aiming toward nuclear weapons, the West wants to stop Iran's 20 percent uranium enrichment program. Western experts say it would not be difficult to upgrade 20 percent enriched uranium to weapons grade. Iran insists its nuclear program is peaceful.
In exchange for discussing enrichment, Iran wants the West to ease sanctions.
President Mahmoud Ahmadinejad recently said the West needs to explain what meaningful concessions it will offer to Iran in return for a halt to 20 percent enrichment.
"If some want us to forgo this right, they should first give their reasons, and secondly (disclose) what they will give the Iranian nation in return," he said.
Schmid has indicated there is no need for preliminary talks. The EU official said the six-power proposal at the Baghdad talks addresses "our key concerns on the 20 percent enrichment activities."
"The next round of talks in Moscow will be successful provided that deputies and experts are able to prepare a specific agenda on the basis of Iran's proposals and those of 5+1," IRNA quoted Bagheri's letter as saying, referring to the five permanent members of the U.N. Security Council and Germany.
"If agreements at each round of talks are not pursued by deputies and experts in an appropriate manner, what will be the guarantee for success of the upcoming talks," IRNA quoted Bagheri as saying.