'Iran will never get bomb', Trump assures Netanyahu

Trump's vow was designed to address Israeli concerns over the nuclear deal between Iran and six world powers - a pact that the new US president has repeatedly criticised on multiple occasions.

"The security challenges faced by Israel are enormous, including the threat of Iran's nuclear ambitions, which I've talked a lot about," Trump said.

"One of the worst deals I've ever seen is the Iran deal. My administration has already imposed new sanctions on Iran, and I will do more to prevent Iran from ever developing - I mean ever - a nuclear weapon."

"With this visit the United States, again, reaffirms our unbreakable bond with our cherished ally, Israel," Trump added.

The Iran nuclear deal was reached in July 2015 and went into effect the next year. Under its terms Iran agreed to dismantle part of its nuclear programme, surrender enriched fuel, and submit to international inspections.

But critics of the agreement, including Netanyahu, have argued then when some of the terms of the deal expire in 10 and 15 years it will leave Tehran on the threshold of building a bomb. 

Relations between Washington and Tehran have deteriorated sharply since Trump took office last month, promising a tough line on what he sees as Iranian belligerency towards US interests and allies.

Trump imposed fresh sanctions on Iran over a 29 January ballistic missile test and officials warned more might follow.

"We are undertaking a larger strategic review," a senior US administration official said, "The launch of the missile was the triggering event."

Washington has also been concerned over Iran's role in regional conflicts, most notably in Syria and Yemen.

Amid the rising tensions, new US Pentagon chief James Mattis described the Islamic Republic as "the single biggest state sponsor of terrorism in the world".