(CNN) Iran is ready for a new relationship with the US -- but the clock is ticking, according to Iranian Foreign Minister Javad Zarif.
In an exclusive interview with CNN's Christiane Amanpour on Monday, Zarif said the Biden administration has a "limited window of opportunity" to re-enter the 2015 nuclear agreement.
"The time for the United States to come back to the nuclear agreement is not unlimited," he said. "The United States has a limited window of opportunity, because President Biden does not want to portray himself as trying to take advantage of the failed policies of the former Trump administration."
Iran has increasingly breached its obligations under the nuclear deal formally known as the Joint Comprehensive Plan of Action (JCPOA), after the Trump administration withdrew the United States from it in 2018.
Last month, the Iranian regime announced that it had resumed enriching uranium up to 20% purity at its Fordow nuclear facility -- far above the 3.67% cap imposed by the 2015 pact, though still short of the 90% that is considered weapons-grade.
Tehran has made clear that any agreement now with the Biden administration will be contingent on a reversal of the harsh economic sanctions imposed by the Trump administration. In December, the hardliner-dominated Iranian Parliament passed legislation obligating the government to further ramp up uranium enrichment, if American sanctions are not eased within two months of the law's adaptation.
Asked just how swiftly Iran could scale back its uranium enrichment program to comply with the nuclear deal if the US lifts sanctions, Zarif said, "8,000 pounds of enriched uranium can go back to the previous amount in less than a day."
US Secretary of State Antony Blinken told NBC in an interview Sunday that the US assessed that it could be "a matter of weeks" before Tehran has enough fissile material for a nuclear weapon if it continues to lift JCPOA constraints even further.
But Iran has publicly insisted that it does not seek a nuclear weapon, a stance that Zarif reiterated on Monday.
"If we wanted to build a nuclear weapon we could have done it some time ago," he said. "But we decided that nuclear weapons are not, would not augment our security and are in contradiction to our, eh, ideological views. And that is why we never pursued nuclear weapons."
A key criticism of the original nuclear deal was that it did not protect neighboring countries from non-nuclear threats by Iran, and did not deter Tehran from funding militias in countries like Yemen, where Iran-backed Houthi rebels have been locked in a bloody war against a Saudi and UAE-led coalition.
At an event for the US Institute of Peace on Friday, US National Security Advisor Jake Sullivan said restoring the deal was a crucial early priority for Biden's administration--- but warned that talks could be affected by the fact that Iran has become a more significant threat than in the early years of the JCPOA.
Iran's ballistic missile capability has "advanced dramatically," he said. "Their recklessness and sponsorship of terrorism in the region has not abated and in some areas has accelerated as well."
Zarif, a former Iranian ambassador to the UN, said that Iran has acted in accordance with dispute mechanisms written into the JCPOA, since the US withdrawal. "Iran used the mechanisms in the nuclear agreement in order to limit its cooperation. If you read paragraph 36, we acted in strict accordance with the nuclear agreement," he said.
He called on the United States to suspend arms sales to regional rivals, and said that the Biden administration needs to stick to the original conditions of the nuclear deal.
"Is the United States prepared to reduce hundreds of billions of dollars of weapons it is selling to our region? Is the United States prepared to stop the massacre of children in Yemen if it wants to talk about the situation in Yemen?" he said. Coalition airstrikes in Yemen have involved US-made bombs, CNN investigations previously revealed.
"The United States has to accept what we agreed upon," Zarif also said. "We decided not to agree on certain things, not because we neglected them, but because the United States and its allies were not prepared to do what was necessary."
According to Zarif, the question over who must take the first step in returning to the JCPOA could be resolved by EU foreign policy chief Josep Borrell.
Borrell could put his "hat on" as coordinator for the Joint Commission of the JCPOA "and sort of choreograph the actions that are needed to be taken by the United States and the actions that are needed to be taken by Iran," he said.