His comments came as Israeli Prime Minister Yair Lapid visited Germany in his latest diplomatic effort to persuade Western powers to ditch the agreement with the Jewish state's arch nemesis Tehran.

Israel has long opposed a revival of the 2015 accord, which has been moribund since then US president Donald Trump unilaterally withdrew in 2018 and reimposed biting sanctions on Tehran.

Momentum that built towards a restored agreement last month has slowed, with the three European nations party to the agreement -- Germany, France and Britain -- expressing doubts about Iran's sincerity over the weekend.

Speaking alongside the Israeli leader in Berlin, Scholz said he regretted that Iran "has not yet given a positive response to proposals" from the Europeans.

"There is now actually no reason for Iran not to agree to these proposals. But we have to note that this is not the case, and will not happen certainly in the near future."

Lapid said it was "time to move past the failed negotiations with Iran.

"They cannot and will not achieve the goal we all share to stop Iran from getting a nuclear weapon."

The 2015 agreement, known formally as the Joint Comprehensive Plan of Action (JCPOA), gave Iran sanctions relief in return for restricting its nuclear programme.

Negotiations underway in Vienna since April 2021 have sought to restore the agreement, by lifting the sanctions on Tehran and pushing Iran to fully honour its prior nuclear commitments.

- 'Critical diplomatic opportunity' -

In a joint statement at the weekend, Germany, France and Britain charged that Tehran "has chosen not to seize this critical diplomatic opportunity".

"Instead, Iran continues to escalate its nuclear programme way beyond any plausible civilian justification", it added. Iran's foreign ministry criticised those comments as "unconstructive."

Further complicating efforts to revive the deal, the UN nuclear watchdog said in a report last week that it "cannot assure" the peaceful nature of Tehran's nuclear programme. Iran reaffirmed Monday its "readiness" to cooperate with the International Atomic Energy Agency.

Before flying to Berlin, Lapid told his cabinet that "Israel is conducting a successful diplomatic campaign to stop the nuclear agreement and prevent the lifting of sanctions on Iran.

"It is not over yet," he added. "There is still a long way to go, but there are encouraging signs."

A senior Israeli official told AFP that Israel's understanding was there would be no return to the deal until mid-November, and they were working with partners on a new strategy.

As well as Scholz, Lapid met Foreign Minister Annalena Baerbock and President Frank-Walter Steinmeier in Berlin.

Israel insists Iran would use revenue from sanctions relief to bolster allied groups capable of attacking Israelis, notably Lebanese Shiite group Hezbollah, and Hamas and Islamic Jihad, two key Palestinian militant organisations.

Last month, the European Union, which acts as the mediator of the nuclear talks, put forward a "final" draft of the agreement.

Iran and the US then took turns to respond to the text, with Washington saying on Friday that Tehran's reply was a step "backwards".

Lapid, whose late father survived the Holocaust, is also travelling with a delegation of survivors who will join him and Scholz on a visit to Wannsee, site of a 1942 conference where top Nazi officials finalised plans to send Jews to death camps.