In 2015, an agreement was made between Iran and the permanent members of the United Nations Security Council (UNSC) for the inspection of Iran's nuclear activities in order to remove the sanctions against Iran.

In 2018, former US President Donald Trump re-imposed sanctions on Iran, saying that they had unilaterally withdrawn from the agreement, and in response to this, Iran stopped its inspection activities.

Since April 2021, negotiations have been held in Vienna under the coordination of the European Union (EU) with the aim of carrying out the agreement properly. Iran objected to the text of the agreement presented in the last negotiations. Mohammad Merendi, adviser to Iran's negotiation team, stated on his Twitter account that the ambiguities and gaps in the text of the agreement will not be accepted. A written statement came from the US that Iran's statement was not constructive. Whether the parties will come to an agreement and what will be the fate of Iran's nuclear issue is eagerly awaited.
 
Source: https://eaworldview.com/2022/09/us-iran-response-nuclear-deal/
https://www.aa.com.tr/tr/dunya/iran-nukleer-anlasma-metnindeki-belirsizlikleri-kabul-etmiyoruz/2676381