However the talks go, Iran's Supreme Leader Ayatollah Ali Khamenei will have the final say on whether Tehran agrees to the proposed tougher UN inspections, a government spokesman said on Monday.
Three legal experts of the International Atomic Energy Agency (IAEA), the UN's nuclear watchdog, were holding talks with Iranian counterparts, said the spokesman of Iran's nuclear energy organisation, Saber Zaimian, quoted by IRNA.
International pressure has been mounting on Iran to sign an Additional Protocol of the nuclear-Non Proliferation Treaty which would allow more intrusive, short-notice inspections of nuclear sites in the country.
Iran denies any plans to build nuclear weapons and the question of whether to sign the protocol has ignited fierce domestic debate.
"The decision about joining the Additional Protocol will be taken based on (our) national interests," government spokesman Abdollah Ramazanzadeh told a weekly news conference.
"The matter will be discussed in the government. The decision will be made in the Supreme National Security Council and after the (Supreme) Leader's approval it would be implemented," he said.
"The decision about joining the Additional Protocol will be taken based on (our) national interests."
-Iranian government spokesman
Khamenei, who succeeded the founding father of the Islamic Republic Ayatollah Ruhollah Khomeini in 1989, is Iran's most powerful political figure.
Khamenei, who is often viewed as siding mostly with hardline clerics in Iran's internal power struggle between reformers and conservatives, has made no public statements recently about whether Iran should join the Additional Protocol.
Moderates in favour
Reformists allied to President Mohammad Khatami's government have begun speaking out in favour of tougher inspections.
Reformist MP Hossein Afarideh, the head of parliament's Energy Commission, was quoted on Monday as saying Iran should sign the protocol to ease international pressure on the country.
"If Iran does not join the protocol, then possibly its case will be sent to the United Nations' Security Council and then naturally the country will face more difficulties," he told the Seda-ye Edalat newspaper.
Hardliners oppose signing the protocol and have even suggested Iran should pull out of the NPT altogether rather than cave in to international demands.
"If the West puts more pressure on Iran, we will withdraw from the NPT. This holds no problem for us," Mohammad Javad Larijani, international affairs adviser to the hardline judiciary, was quoted in the Resalat newspaper on Sunday.
Ramazanzadeh said Iran had a "positive view" on the talks.
Tehran has insisted it should get access to Western nuclear technology to develop atomic energy in return for signing the protocol.