Haley: US 'has grounds' to revoke Iran nuclear deal

The United States "has grounds" to revoke the Iran nuclear deal, American UN envoy Nikki Haley said on Tuesday.

Speaking at an event hosted by a conservative think tank in Washington D.C, Haley emphasised President Donald Trump's authority over the matter.

"The entire world thinks the JCPOA is untouchable, but it's not," Haley said at the American Enterprise Institue, using the formal acronym for the nuclear pact.

"What I am saying is should he [Trump] decide to decertify, he has grounds to stand on," Haley said. "It's very easy to just talk about compliance and the JCPOA," she added.

The UN envoy also criticised the nuclear pact and alleged that Iran had breached its terms with its most recent ballistic missile test, however indicated that the US Congress would have the final say on the matter.

"What happens next is significantly in Congress's hands," Haley said.

Despite US agitation at Iran's perceived breaching of the pact, Iran has said that it is willing to continue with the deal as long as its five other signatories remain committed.

Tehran recently dismissed murmurings from the US about possible nuclear inspections, with Iranian President Hassan Rouhani saying that such investigations are not necessary under the terms of the accord.

A report released by the International Atomic Energy Agency bolstered the Iranian position whe it confirmed that Tehran was keeping within the terms of the agreement.

Ambassador Haley, however, emphasised that US legislation requires the president not only to certify the absence of "technical violations," but also to guarantee that continuing with the deal is "appropriate and proportionate" to Iran's actions.

Following Iran's ballistic missile tests in February, president Trump said "nothing is off the table" in dealing with Tehran. The White House added at the time that Iran had been put "on notice" over the tests.

The landmark nuclear accord, agreed under the presidency of Barack Obama in 2015, saw international sanctions eased in exchange for stringent controls on Iran's nuclear programme and closer IAEA inspections. 

Since the agreement, the US has still maintained seperate sanctions against Iran, with both Obama and Trump having added to these punitive measures.

"Judging any international agreement ends and begins with the nature of regime that signs it," Haley said.

"You can look at any place in the Middle East where there are problems, and there are Iranian tentacles there," she said.