The announced visit is the latest in the Jewish state's push to sway Western powers from a deal to return to the landmark 2015 deal with Tehran.

Israel says a deal would facilitate the funding of Iran-supported militants, while not preventing Tehran from developing a nuclear weapon -- a goal Iran has always denied.

Mossad chief David Barnea will "be visiting Washington in a week to participate in closed door meetings in Congress on the Iran deal," a senior Israeli official told AFP on condition of anonymity, without providing further details.

Earlier Sunday, Prime Minister Yair Lapid said that Israel's "diplomatic fight" against the deal included its national security advisor and defence minister holding recent meetings in the United States.

"We are making a concerted effort to ensure the Americans and Europeans understand the dangers involved in this agreement," Lapid said, stressing what was signed in 2015 was "not a good deal," and that the one currently being formulated entails "greater dangers."

In 2018, then-US president Donald Trump unilaterally withdrew from the agreement designed to prevent Iran from developing a nuclear weapon.

His successor Joe Biden has sought to return to the deal, and after almost a year-and-a-half of talks, recent progress has put the Jewish state on edge.

According to Lapid, a new agreement would have to include an expiration date, and tighter supervision that would also "address Iran's ballistic missile program and its involvement in terrorism throughout the Middle East."

"We can reach such an agreement if a credible military threat is put on the table, if the Iranians realise that their defiance and deceit will exact a heavy price," Lapid said, adding that the army and Mossad had "received instructions from us to prepare for any scenario".

On Wednesday, Lapid said a new deal would "give Iran $100 billion a year" that would be used by Iran-backed militant groups Hamas, Hezbollah and Islamic Jihad, and noted he was holding talks with the leadership of Britain, France and Germany on the issue.