Iranian President Hassan Rouhani on Tuesday rejected Mohammad Javad Zarif’s resignation as the country’s foreign minister, reported Reuters, citing a post on Rouhani’s Instagram page.

Zarif announced his resignation on his own Instagram account on Monday: “I am apologising you for all the shortcomings … in the past years during my time as foreign minister. … I thank the Iranian nation and officials.”

Zarif has provided no explanation.

He was the official who negotiated the 2015 Iran nuclear deal on the Islamic Republic’s behalf.