"Iran does not want to substitute them as negotiating partners," foreign ministry spokesman Hamid Reza Asefi said of the so-called EU-3, who have been engaged in close to two years of tough talks with the Islamic republic.

"We will continue negotiating with them, but on the other hand we will not restrict our negotiations to being with just these three countries," he added, saying Iran had also been talking with countries such as Japan, Malaysia and South Africa.

"We want to have negotiations with other countries, it is up to the Europeans not to remove themselves from the negotiations," he said, accusing the EU-3 of refusing to recognise Iran's right to the nuclear fuel cycle.

The EU-3 have been trying to convince Iran to totally abandon fuel cycle work -- which Iran says is for peaceful purposes only but which could be diverted to military use -- in exchange for a package of incentives.

Iran has rejected such a deal, arguing it has the right to an atomic energy programme and fuel cycle as a signatory of the nuclear Non-Proliferation Treaty (NPT).

According to Asefi, Iran's "main negotiating partner is the International Atomic Energy Agency (IAEA)", the Vienna-based UN nuclear watchdog.