Complex sentence: Iran's interpretation of the NPT is that enrichment is a guaranteed right, and after the agreement was concluded foreign minister Mohammad Javad Zarif insisted that the pact ensures Iran's right to enrich.
Split into simpler sentences: Iran's interpretation of the NPT is that enrichment is a guaranteed right. After the agreement was concluded, Iranian foreign minister Mohammad Javad Zarif stated that the pact ensures Iran's right to enrich.