Iran is willing to negotiate with the United Nations atomic watchdog over its compliance with safeguards on its nuclear programme but will not do so “under pressure and intimidation”, the country’s top diplomat says.

Iranian Foreign Minister Abbas Araghchi met International Atomic Energy Agency (IAEA) chief Rafael Grossi in Tehran on Thursday, describing their interaction as “important and straightforward” in a post on X.

Grossi told Iranian officials that the UN watchdog wants to see “concrete, tangible and visible results” during discussions on Iran’s nuclear programme.

After the meeting, Araghchi – who served as Iran’s chief negotiator in the talks that led to a 2015 nuclear deal with world powers – said his country “has never left the negotiation table on its peaceful” nuclear programme.

“The ball is in the EU/E3 court,” Araghchi wrote, referring to the United Kingdom, Germany and France.

Iran was “willing to negotiate based on our national interest & our inalienable rights, but NOT ready to negotiate under pressure and intimidation”, he posted on X.

In a joint news conference with Mohammad Eslami, the head of the Atomic Energy Organization of Iran, Grossi said that given the “serious circumstances in the region”, he was determined to make the talks “successful”.

The IAEA chief’s visit comes weeks before United States President-elect Donald Trump takes office in January.

During Trump’s previous term as president, the US unilaterally withdrew from the 2015 agreement that saw Iran scale back its nuclear programme in exchange for a lifting of international sanctions against its economy.

Eslami said he looked forward to “mutually constructive and effective talks under the present circumstances”.

But he warned of “immediate countermeasures” against any resolution by the IAEA’s board of governors that interfere with Iran’s nuclear programme.

Grossi said, “The fact that international tensions and regional tensions do exist – this shows that the space for negotiation and diplomacy is not getting bigger, it is getting smaller.”

The IAEA chief is also expected to meet President Masoud Pezeshkian, who told the UN General Assembly in September that he wants to open a “constructive” chapter in his country’s international relations and was “ready to engage” with the West over Iran’s nuclear programme.

Before his trip, Grossi had appealed to Iran’s leaders to take steps to resolve longstanding issues with his agency, including a push for more monitoring cooperation at nuclear sites and an explanation of uranium traces found at alleged undeclared sites.

But little has come from his efforts and with the return of Trump, who is widely expected to restore a maximum pressure policy on Iran, Grossi’s trip should provide indications of how Iran wants to proceed in the coming months.

Reporting from Tehran, Al Jazeera’s Resul Serdar said that while a lot was at stake during Grossi’s visit, the possibility of a breakthrough was “quite low”.

“There are major sticking points” between the two parties, he said, adding that the “mistrust” is also significant.

Aside from issues about monitoring, the IAEA is also accusing Iran of denying UN nuclear inspectors accreditation, Serdar reported.

“In turn, Iran is accusing the IAEA of politicising the process and behaving like they are acting on behalf of third parties, particularly on behalf of Israel,” he added. “Today we are not expecting this mistrust to be overcome.”

Iran’s work on uranium enrichment has been seen by the West as a disguised effort to develop nuclear weapons capability. Tehran is now enriching uranium up to 60 percent fissile purity, close to the roughly 90 percent required for a nuclear bomb.

But Iran has long denied any nuclear bomb ambitions, saying it is enriching uranium for civilian energy uses only.

Grossi has said that while Iran does not currently have a nuclear weapon, it does have plenty of enriched uranium that could eventually be used to make one.