International Atomic Energy Agency Director Rafael Grossi said on Tuesday that the agency was taking the Islamic Republic’s recent remarks about nuclear weapons very seriously.

“Loose talk about nuclear weapons is extremely serious for me. And I think it should stop. We are moving closer to a situation where there is a big, huge question mark about what they are doing and why they are doing it,” Grossi told The Guardian following a meeting with U.K. Foreign Secretary David Cameron.

Over the weekend, an Iranian lawmaker representing a district close to Iran’s Natanz nuclear facility said the Islamic Republic might already possess a nuclear bomb.

“In my opinion, we have achieved nuclear weapons, but we do not announce it,” said Ahmad Bakhshayesh Ardestani.

An “increasing number” of Iranian politicians have called for the country to develop nuclear weapons, The Guardian reported.

The first was Kamal Kharrazi, foreign policy adviser to Supreme Leader Ali Khamenei, who said on May 9: “We have no decision to produce a nuclear bomb, but if the existence of Iran is threatened, we will have to change our nuclear doctrine.”

Kharrazi’s comments came only two days after Grossi visited Iran and said that the IAEA and the Islamic Republic had agreed on “tangible and operational steps” to implement an earlier agreement between the two countries regarding oversight of Iran’s nuclear program.

Kharrazi’s remarks were directed toward last month’s retaliatory strike by Israel on Iran, which destroyed parts of the Islamic regime’s Shikari Air Base near Isfahan.

The attack came five days after Iran launched an unprecedented assault on Israel involving more than 300 drones and missiles.