"There is no reason to criticise what America did at the weekend. Yes, it is not without risk. But leaving things as they were was not an option either," Merz said in a speech to the Federation of German Industries.

Labelling Iran a "terror regime", he added that "Israel has been under attack from Iran for years, if not decades, including through the financing of Hamas, Hezbollah, militias in Iraq and in many other places around the world".

The US strikes came after Israel launched large-scale attacks on June 13 targeting Iran's missile and nuclear facilities, as well as military leaders and security services.

Iran's uranium enrichment has for decades caused tension with the West and Israel, which fear the drive is aimed at making an atomic bomb, a charge denied by Tehran.

While France has expressed "concern" over the US strikes, Merz said they were justified by "evidence that Iran (was) continuing to move forward with building a nuclear weapon".

"No one needs bunkered facilities up to 100 metres below ground for the enrichment of uranium for peaceful purposes," he said.

Merz last week also expressed strong support for Israel's campaign against Iran, describing it as "the dirty work Israel is doing for all of us".

The German chancellor on Sunday called on Iran to "immediately enter into negotiations with the US and Israel and to find a diplomatic solution to the conflict", according to his spokesman Stefan Kornelius.

In a joint statement with the leaders of France and Britain, Merz also urged Tehran "not to take any further action that could destabilise the region".

"We call upon Iran to engage in negotiations leading to an agreement that addresses all concerns associated with its nuclear programme," the leaders said in their statement.