Iran will abandon more of the commitments it made under the 2015 nuclear deal if the agreement's remaining European signatories do not shield Iran's economy from US sanctions, Tehran's top diplomat said on Monday.
"It is meaningless to continue unilateral commitments to the deal if we don't enjoy its benefits as promised by the deal's European parties," Foreign Minister Javad Zarif said.
Speaking after talks with his Russian counterpart in Moscow, Mr Zarif said Iran would "be complying with its obligations in full when the Europeans comply with theirs in full".
Tehran will take a "strong step" away from the 2015 deal if its European signatories cannot offer it new terms by the end of the week, government spokesman Ali Rabiei said on Monday, echoing Mr Zarif's position.
Tehran wants Europe to offer it a way of circumventing US sanctions so it can sell its crude oil on the global market. US President Donald Trump imposed the measures after Washington withdrew from the nuclear deal in May 2017, severely crippling Iran's oil sales.
Mr Rabiei described Iran's strategy as "commitment for commitment".
"Iran's oil should be bought and its money should be accessible to return to Iran," Mr Rabiei said. "This is the agenda of our talks."
It is unclear what the terms of negotiation are. In theory, anyone caught buying Iranian crude oil would be subject to US sanctions and potentially locked out of the American financial market.
Iran has already gone over limits set by the 2015 deal. The International Atomic Energy Agency confirmed last week that Iran's stockpile of low-enriched uranium still exceeds the amount allowed by the Joint Comprehensive Plan of Action, or JCPOA as the deal is known.
The UN agency also said Iran continues to enrich uranium up to 4.5 per cent, above the 3.67 per cent allowed.
Enriched uranium at the 3.67 per cent level is enough for peaceful pursuits and is far below the weapons-grade level of 90 per cent. At the 4.5 per cent level, the uranium can help power Iran's Bushehr reactor, the country's only nuclear power plant.
It is not known what further steps Iran will take, though these could involve restarting advanced centrifuges prohibited by the deal or further bumping up its enrichment of uranium. Iran insists the steps it has taken so far are easily reversible.