Lots of people know that Iran has threatened to withdraw from the NPT, should the E3 refer Iran’s JCPOA noncompliance [as the E3 characterizes it] to the UNSC. But Zarif clarified Iran’s position in this Der Spiegel interview:

DER SPIEGEL: How would Iran react to the reinstatement of UN sanctions?

Zarif: President Hassan Rohani clarified the actions we will take in a letter to the treaty partners.

DER SPIEGEL: Could you explain for our readers?

Zarif: Your readers should know that the Europeans will be responsible for all the consequences.

DER SPIEGEL: Iran has threatened to withdraw from the Nuclear Non-Proliferation Treaty (NPT) if that happens.

Zarif: It’s mentioned in the letter.

DER SPIEGEL: Does that mean that Iran would head in the direction of building a bomb?

Zarif: No. Our decision not to build a bomb does not derive from NPT. It derives from our own moral and strategic convictions.