Wadephul said he had delivered the message to his Iranian counterpart in a phone call on Monday together with the French and British foreign ministers and the European Union's chief diplomat.

"We, the E3 states, remain ready to negotiate a solution," Wadephul said, with reference to the European grouping of Britain, France and Germany.

"Iran must now act urgently," he said, calling for "verifiable and confidence-building measures", such as a commitment from the government in Tehran not to pursue nuclear weapons capabilities.

"It is never too late to come to the negotiating table if you come with honest intentions," Wadephul said in a press conference alongside the Jordanian foreign minister.

Israel's initial attack launched on Friday hit about 100 targets in Iran including nuclear facilities and military command centres.

The attack came as the United States and Iran were due to meet in Oman to pick up negotiations towards an agreement on the Islamic republic's nuclear programme.

But the talks, set for last Sunday, were abandoned, with the government in Tehran saying discussions were "meaningless" while the conflict with Israel continued.

Tehran insists its uranium-enrichment activities are peaceful, but Western allies fear they are aimed at developing atomic weapons.

Iran has retaliated to the Israeli strikes, launching its own drone and missile attacks.

Since Friday, at least 24 people have been killed in Israel and hundreds wounded, according to the office of Israeli Prime Minister Benjamin Netanyahu's office.

Iran said on Sunday that the Israeli strikes had killed at least 224 people, including military commanders, nuclear scientists and civilians. It has not issued an updated toll since.