Former U.S. Secretary of State John Kerry acknowledged on Wednesday that he has done outside diplomacy with top Iranian officials to save the 2015 Iran nuclear deal, pushing the regime to negotiate its ballistic missile program.

Promoting his new book Every Day Is Extra, Kerry said he has met with Iranian Former Minister Javad Zarif around three or four times in recent months, defying the Trump administration, which pulled out of the nuclear deal in May and has re-imposed sanctions on the Islamic Republic.

“What I have done is try to elicit from [Zarif] what Iran might be willing to do to change the dynamic of the Middle East for the better,” Kerry told radio host Hugh Hewitt. “How does one resolve Yemen; what do you do to try and get peace in Syria? Those are the things that really are preoccupying him because those are the impediments to Iran’s ability to convince people its ready to embrace something different.”

“I’ve been very blunt to Foreign Minister Zarif,” said Kerry. “I told him, ‘Look, you guys need to recognize the world does not appreciate what’s happening with missiles, what’s happening with Hezbollah, what’s happening with Yemen. You’re supporting an ongoing struggle there.”

Additionally, Kerry blasted the current administration for its Iran strategy. “It appears right now as if the administration is hell-bent … to pursue a regime-change strategy” in Iran, which could “bring the economy down and try to isolate further.”

However, he himself has come under severe criticism by supporters of the Trump administration, who point out that giving advice to a hostile foreign power is inappropriate and possibly a violation of the 1799 Logan Act, a U.S. law that prohibits private diplomacy. Former National Security Advisor Michael Flynn first came under fire from Democrats for the same offense with respect to his talks with Russia prior to U.S. President Donald Trump’s inauguration.