Iranian President-elect Ebrahim Raisi said Monday that he opposes talks on limiting Tehran’s ballistic missile program and its support for regional proxy forces. Speaking in the Iranian capital at his first news conference since winning Friday’s presidential election, Raisi also said he is not willing to meet President Biden, even as the two sides work to revive a 2015 nuclear deal between Iran and world powers.

When asked by a reporter whether he was willing to meet Biden, Raisi simply said, “No.” He added that Iran’s ballistic missiles and regional presence are “not negotiable.”

He made the comments a day after Iranian authorities said they had temporarily shut down the country’s only nuclear power plant because of unspecified technical difficulties. A statement from the Atomic Energy Organization of Iran late Sunday said the Bushehr plant on the Persian Gulf was shut down following a “technical defect” and would be disconnected from the national power grid for several days.

Human rights groups have linked Raisi, who most recently served as chief of Iran’s judiciary, to numerous episodes of repression over decades and said he played a central role in mass killings of dissidents in the late 1980s. Raisi had “been a member of the ‘death commission’ which forcibly disappeared and extrajudicially executed in secret thousands of political dissidents in Evin and Gohardasht prisons near Tehran in 1988,” Amnesty International said in a statement Saturday, calling for Raisi to be investigated under international law.

Asked about the allegations Monday, Raisi said, “I have always defended people’s rights since the beginning of my responsibilities. Human rights have been a pivotal point for me.”