Eslami made the remarks in a meeting with the International Atomic Energy Agency (IAEA) Director General Rafael Grossi in Austria’s Vienna on Monday.

The top nuclear official slammed the biased approach taken to Iran by Western governments, saying, "By resorting to sanctions ... these countries are trying to use the IAEA's mechanisms to mount pressure on Iran."

"Brutal political pressures exerted by Western countries on Iran will not bear fruit and the Islamic Republic will not allow any politically-motivated pressure to go unanswered," the official stressed.

He urged Grossi to keep the IAEA on an impartial and professional track and does not allow the Western states to use the nuclear agency's reports as an excuse to put pressure on Iran.

Following the meeting, Grossi said in a post on X social media platform, formally known as Twitter, that his meeting with Eslami was "important."

He added that the IAEA is willing to "engage and make concrete progress" in accordance with an agreement signed in Tehran in early March "to provide credible assurances that Iran's nuclear program is exclusively peaceful”.

The meeting came as tensions between Tehran and the IAEA have been rising after Iran's move to bar a number of the nuclear watchdog's inspectors from being assigned to the country.

Grossi had criticized Tehran for effectively barring several of its most experienced inspectors from monitoring Iran's nuclear program. 

The nuclear agency's chief described the move as "disproportionate and unprecedented", claiming that Iran's unilateral measure affects the IAEA's "normal planning and conduct" verification activities in the country and "openly contradicts the collaboration that should exist between the nuclear agency and Tehran".

In response, Iranian Foreign Ministry Spokesman Nasser Kana'ani slammed Washington and the three European parties to the 2015 nuclear deal of misusing the IAEA to achieve their own purposes, saying the UN body has been politicized despite Tehran’s positive and constructive interaction with the nuclear agency.

He linked the move to an attempt by the US and three European states to misuse the UN body “for their own political purposes”.

"Unfortunately, despite Iran's positive, constructive and continuous interaction with the IAEA, the three European countries and the United States abused the Agency's Board of Governors for their own political purposes with … the aim of damaging the atmosphere of cooperation between Iran and the Agency," he added, referring to the UK, France and Germany. 

The diplomat stated that Iran has previously warned against the consequences of such efforts to politicize the UN nuclear agency.

He reiterated that Tehran made the decision in accordance with Article 9 of the agreement between Iran and the IAEA for the application of safeguards in connection with the Treaty on the Non-Proliferation of Nuclear Weapons.

The spokesman once again called on the Western countries to stop abusing international organizations, including the IAEA, and allow such world bodies to carry out their "professional and neutral" activities under no political pressure.

“Of course, Iran will continue its positive interaction within the framework of the bilateral agreements that have been made, and emphasise the necessity of the nuclear agency’s neutrality,” he continued.

Iran’s act was a response to a call led by the US, the UK, France and Germany at the IAEA’s Board of Governors for Tehran to work immediately with the UN watchdog on issues including explaining "uranium traces found at undeclared sites". The IAEA’s Board of Governors on Wednesday issued a Western-sponsored statement which accused Iran of non-compliance with its safeguards commitments. The document, signed by 62 member states of the agency, called upon Iran to take steps to address outstanding safeguards issues and provide the IAEA with information concerning its new nuclear facilities.

Tehran has repeatedly rejected all accusations levelled by the West over the existence of undeclared nuclear activities or material in Iran, describing the allegations by the US and its European allies as a propaganda campaign against the country's peaceful nuclear program.

Iran proved the peaceful nature of its nuclear program to the world by signing the 2015 nuclear deal with six world powers. However, Washington’s exit in May 2018 and its subsequent re-imposition of sanctions against Tehran left the future of the agreement in limbo.

Iran has always had full cooperation with the IAEA and allowed it to visit the country’s nuclear sites, but calls the nuclear agency's approach unconstructive and destructive. Tehran has asked the watchdog to avoid politicizing the issue and focus on technical aspects in line with the organization’s mandate.

Iranian officials have repeatedly called on Grossi to stop Israeli-influenced attitude, and emphasized that Tehran would never surrender to the political behavior of the UN nuclear watchdog that is affected by the Zionist pressures.

Tehran has on many occasions voiced its readiness to resolve differences with the UN nuclear body within a framework of constructive and mutual interaction and technical collaboration.