"The Islamic Republic of Iran always seeks interaction and dialogue, but will strongly defend the rights of the nation," First Vice President Es'haq Jahangiri said at an event in Tehran, ISNA reported.
He said all measures taken by Iran to scale back its commitments under the agreement are "reversible", if the European members of the pact fulfill their obligations.
Tehran said on Sunday it will shortly boost its uranium enrichment above the 3.67% cap set by the nuclear accord and added that it would keep reducing its commitments every 60 days until Europe upholds its side of the deal, Financial Tribune reported.
The Europeans, who object to US President Donald Trump's withdrawal from the deal, have so far failed to salvage the pact by shielding Iran's economy from renewed US sanctions.
Jahangiri expressed hope that Britain, France and Germany would use the time and opportunity available "so that we could reach an understanding".
He also said the Americans did not allow Iranian people to benefit from the deal even before their official exit.
Legitimate Measures
Foreign Ministry Spokesman Abbas Mousavi said Iran has not closed the path to diplomacy to resolve issues surrounding the nuclear agreement, but the onus is on the remaining signatories to pull their weight.
"The door to diplomacy remains open, but we will not compromise on the rights of the nation and the country," he told a press briefing in Tehran, IRNA reported.
"We have already said if the efforts and measures being taken by the other side succeed in satisfying our needs and demands, we will reverse our actions," he said, adding that Iran's decision to reduce some of its nuclear commitments are based on the legal mechanisms enshrined in the deal—technically called the Joint Comprehensive Plan of Action.
Under a dispute process, Iran can argue the US pullout and sanctions campaign constitute "significant non-performance" and "treat the unresolved issue as grounds to cease performing its commitments".
Mousavi also ruled out the possibility of Iran renegotiating the agreement, saying that Washington should end its campaign of "economic terrorism" against the country if it wants to rejoin meetings of the Joint Commission—which is tasked with monitoring the implementation of the deal.
"We will not accept any new commitments," he said, adding that America's return to its obligations would be considered a "positive step".
The spokesman called the nuclear deal a "great and important achievement" for the Iranian nation, as well as regional and global peace and stability, noting that it would be a "matter of regret" if it falls apart.