Khamenei, Iran's top leader, said on Monday he had ordered preparations to increase uranium enrichment capacity if the nuclear agreement falls apart after the US withdrawal, and he vowed never to accept limits on Tehran's ballistic missile program.
The material shown did not present a breach of the deal but European leaders suggested it showed evidence of Iran's nuclear programme before 2015, which, they said, only reinforced the need for the agreement, which includes regular inspections.
Under the agreement with the United States, France, Germany, Britain, Russia and China, Iran was given the strictly limited uranium enrichment capacity to satisfy the powers that it could not be used to develop atomic bombs.
Uranium must be enriched to around 90 percent for use in nuclear weapons.
Israeli Prime Minister Benjamin Netanyahu lands Monday in Germany to meet with Chancellor Angela Merkel before heading in the evening to Paris for his next set of talks with President Emmanuel Macron.
Katz addressed Tehran's threat to restart uranium enrichment at an "industrial level" if the 2015 pact falls apart.
European governments have been trying to salvage the agreement ever since the United States announced its withdrawal last month and said it would reimpose sanctions on foreign companies working in the Islamic republic by November. "The Arabs and Israel surely would be there too", he added.
In May, US President Donald Trump pulled the US from the landmark 2015 nuclear deal between Iran and the world powers.
At a press conference following their talk, Ms Merkel said: "Our meeting focused on an worldwide issue, the Iran agreement".
One speaker at the protest said that "Israel puts over a million people in Zionist concentration camps, yet calls itself the only democracy in the Middle East".
The nuclear deal and lifting of punishing nuclear related worldwide sanctions created optimism in Iran after years of economic isolation.
In his speech marking the 29th anniversary of the death of Iranian revolutionary leader Ayatollah Ruhollah Khomeini, Khamenei insisted on resisting US pressure and again warned of a harsh response if Iran came under attack.
"We support Israel's right to security and have said this to Iran at all times", she said.
Merkel said she agreed that Iran's activities in the Middle East were a concern, particularly for Israel's security.
"Iran calls for our destruction but it is also seeking nuclear weapons to carry out its genocidal designs".