Iran's foreign minister defended Tuesday what he said was a "balanced" nuclear deal with world powers, telling lawmakers there was a need to accept the negotiations had required compromise.
In a speech to parliament Mohammad Javad Zarif emphasised that last week's agreement would secure the lifting in coming months of UN and Western sanctions imposed on Iran over its nuclear programme.
In return, Iran has agreed to put curbs on its atomic activities for at least a decade but it will continue to enrich uranium and be allowed to pursue research and development of more modern nuclear technology.
The deal and restrictions, including a more rigorous inspection regime, aim to remove Western concerns that Iran is seeking an atomic bomb -- an allegation it has always denied.
Zarif, who led Iran's negotiating team, was feted in street celebrations in Tehran after the deal was announced last Tuesday, but members of the conservative-dominated parliament have proved a tougher sell.
In a sign of their scepticism, just days before the final negotiations started in Vienna, lawmakers passed a new law which they said was to defend the nuclear programme, but which the government opposed.
Some hardliners in parliament have railed against the diplomacy, arguing that too many concessions were made.
But Zarif said that the long-running talks could never have satisfied Iran's or the West's every demand.
"We should not forget that any deal is a give and take and each side gives up part of its demands to realise the more important part until what has been given and received is balanced," he said.
"Iran's key objectives on which we insisted are what we gained. For the other side the key demands were to prevent Iran from reaching nuclear weapons through limitations and supervision."
Suggesting that Iran had gotten the better side of the bargain, and reiterating that it had never sought nuclear weapons, Zarif added: "What they gained was a vain effort to get what was already acquired.
"Our biggest achievement is the stamp by the UN Security Council confirming (uranium) enrichment in Iran."
The UN Security Council unanimously adopted a resolution on Monday endorsing the historic deal, clearing the path to remove the sanctions that have crippled Iran's economy in recent years.
It marks formal UN approval for the hard-won agreement reached between Iran and the five permanent members of the Security Council plus Germany.