Image copyright Getty Images Image caption Iranian President Hassan Rouhani will attend talks in Washington
The US has stressed that it will pursue other options should negotiations with Iran fail.
It suggests the deployment of new economic sanctions, threatening anyone who trades with Iran, even in the nuclear sector.
Meanwhile, efforts are underway for US diplomats to meet the Iranian negotiators in a bid to re-establish Tehran’s participation in UN-sponsored talks.
The talks were suspended after US President Donald Trump withdrew from an international nuclear deal.
The talks, along with US efforts to re-impose sanctions, are intended to show Iran that it faces a strong alternative to the 2015 nuclear deal, Iran’s deputy foreign minister Abbas Araghchi said on Wednesday.
After the previous round in March, the European Union and France had come out in favour of trying to reach a new agreement and Britain, Germany and the European Union – which are signatories to the agreement – have agreed to hold off on the potential imposition of new economic sanctions.
Mr Araghchi on Wednesday also said Iran was prepared to resume cooperation with UN nuclear inspectors but would only do so when the agreement was fully implemented.
Iran fears that if the deal does not hold, there would be no guarantee that the International Atomic Energy Agency would continue to oversee Iran’s nuclear activities.
President Hassan Rouhani told a public event on Wednesday that the agreement was “over”, accusing the US of being “without any bargaining power”.
“Whether they believe it or not, we have ended the Iran nuclear deal. We say from now on we are on our own path,” Mr Rouhani added.
“No-one can see that we are on our own path, no-one can see we will face sanctions and come out unscathed”.
In an interview with Reuters, the US ambassador to the UN, Nikki Haley, said Iran was “one of the primary actors” in facilitating terrorism, calling it “this false flag, untrustworthy, and dishonest regime”.
Image copyright Getty Images Image caption Mr Araghchi also says there is a rift between Iran and the EU over what will follow the end of the nuclear deal
Iran has said there is a division between it and the EU over how to respond to the end of the nuclear deal, with the EU saying it will wait for a decision by the UN Security Council.
Mr Araghchi said Tehran was not opposed to the European Union continuing to import oil from Iran but would only do so if it complied with the 2015 nuclear deal.
On Wednesday, Iran’s Foreign Minister said the country was sending a team to Geneva to discuss the nuclear issue with the UN nuclear agency.