The Jerusalem Post reported earlier this week that the IAEA was close to closing or at least shelving its probe into the undeclared nuclear site.
Western powers are particularly concerned because UN Security Council restrictions on missiles lasts until October 2023 after which Iran is free to pursue its ballistic missile activity.
In the last few decades, there was a battle to stop Tehran from being able to develop a nuclear weapon.
As the Islamic Republic advances in its quest for nukes, military intel chief Aharon Haliva said the IDF is remaining "ready at all times."
Tajani arrived in Israel just as Prime Minister Benjamin Netanyahu returned from a trip to Italy.
Grossi's statements came after extended meetings with key officials in Iran over the weekend.
"Are we forbidden from defending ourselves? We are obviously permitted to do this," Prime Minister Benjamin Netanyahu told his cabinet in a televised speech Saturday night.
Iran is supposed to provide access to information, locations and people, suggesting a vast improvement after years of Iranian stonewalling.
Israel is also expected to ask Germany to designate the Iran Islamic Revolutionary Guard as a terror entity.
The Iranians are leveraging every opportunity to acquire strategic military capabilities and hardware that were previously out of their reach.