In his second interview with an international outlet in two days, Iran’s Foreign Minister Mohammad Javad Zarif has warned that the Islamic Republic could leave the July 2015 nuclear deal if the US withdraws.

Zarif told Al Jazeera in New York, “If Washington decides to pull out of the deal, Iran has the option of withdrawal and other options.”

The Foreign Minister’s statement is a toughening of Tehran’s line. While President Hassan Rouhani also shifted in August to raise the possibility of Iranian departure, he has focused recently on separating Europe from the US as Tehran remains in the agreement with the 5+1 Powers (US, UK, France, Germany, China, and Russia). Last week Rouhani headlined “moderation” in his speech to the UN General Assembly, following Donald Trump’s aggressive condemnation of the “embarrassment” of the deal.

On Wednesday, Zarif told the Associated Press that Iran will not renegotiate the deal — a line put out by American officials after Trump’s UN address — but was vaguer on possible withdrawal if the US left: “We’re not bound by that agreement and we will then decide how we want to deal with it.”

He indicated that Iran could quickly return to enrichment of 20% uranium, which Tehran gave up under the Joint Comprhensive Plan of Action: “If the deal is broken, then Iran has many options, one of which would be to have an unlimited yet peaceful nuclear energy program.”

See Iran Daily, Sept 28: Zarif Blasts Trump, Says No Renegotiation of Nuclear Deal

Al Jazeera initially report that Zarif had said Iran would definitely follow a US withdrawal, but revised it to the possibility of departure after an Iranian official said Zarif had been misquoted.