But Iran has said it may go further, by enriching uranium to a grade of as much as 20 percent if it does not see sanctions relief by a July 7 deadline - a move that would force Europe to take a tougher stance and which could trigger its own sanctions.
Elsewhere on the sidelines of the deal, Israeli leader Benjamin Netanyahu also chipped in, telling European signatories on the JCPOA that they had committed to act "the moment Iran violates the nuclear agreement" by triggering automatic sanctions.
Additionally, the senators asked the administration to invoke the snapback mechanism in United Nations Security Council resolution 2231.
Ryan Bohl, political analyst at USA risk assessment company Stratford, said there remained European consensus on giving more time for Instex to work but if Iran keeps wanting more, "the hawks in Europe will gain the upper hand".
European powers - notably Britain, France, and Germany - scrambled to preserve the JCPOA and to prop up Iranian trade after President Donald Trump withdrew from the Obama-era nuclear deal and imposed new sanctions to cripple Iran's economy.
Under the nuclear deal, Iran agreed to have less than 300 kilograms (661 pounds) of uranium enriched to a maximum of 3.67%.
But if the announcement does not press the European Union into helping to restore the oil revenue lost to U.S. sanctions, Tehran may have set itself on a course of more serious breaches of its nuclear limits.
Done Deals: Hector Herrera To Atletico Madrid, Rodri To Manchester City
There has not yet been an official announcement from the Premier League champions, but Rodri is no longer an Atletico player. City also missed out on Jorginho last summer and were previously interested in Fred prior to his move to Manchester United.
As we have shown in political, worldwide and field areas, Iran is an important actor in global level and we won't let any side to talk with Iranian nation except with a respectful language.
"One mustn't dramatise the situation", Ryabkov, whose country is a close ally of Tehran, said in comments reported by Russian news agencies. "We will increase beyond 3.67 per cent to as much as we want, as much as is necessary, as much as we need".
Attacks in the Strait of Hormuz, a vital waterway for oil shipments from the Middle East, and the Iranian downing of an American drone have raised concerns of another war in the region as the standoff escalates. USA sanctions have deterred European businesses from conducting trade with the country. It began firing at the Iranian ships there.
Iranian Foreign Minister Mohammad Javad Zarif had a one word quip in response to that on Tuesday.
The United Nations' International Atomic Energy Agency has confirmed that Iran had breached the JCPOA. The Iranians allegedly fired on the helicopter and the Vincennes gave chase, the Navy said. It fired missiles, killing all 290 people on board.
In this photo released by the official website of the office of the Iranian Presidency, President Hassan Rouhani speaks in a cabinet meeting in Tehran, Iran, Wednesday, July 3, 2019.