Ebrahim Raisi has been sworn in as as the Islamic Republic's new president.
Raisi read the inauguration oath at the country's parliament in Tehran on Thursday, with his hand on a Quran, before adding that he will make Iran stronger and engage with the rest of the world.
He was declared the winner of a June election characterized by low turnout and allegations of election manipulation.
Raisi was a significant figure in a "death commission" that ordered the executions of hundreds of political prisoners in 1988.
He previously served as Tehran's prosecutor general from 1989 to 1994, and as the judiciary's first deputy chief from 2004 to 2014.
Raisi is perceived to be more hardline and anti-Western than his predecessor, Hassan Rouhani, who oversaw the signing of the 2015 Iranian nuclear deal, formally known as the Joint Comprehensive Plan of Action.
The agreement, signed by numerous world powers, including the U.S., removed sanctions against Iran in exchange for limits on its nuclear program.
The U.S. government has cited Raisi's role in a "brutal" crackdown on Iran's Green Movement demonstrators following the 2009 election. In 2019, it sanctioned a number of Iranian officials, including Raisi, for human rights violations.
According to U.S. reports, the judiciary sanctioned the execution of child offenders and imprisoned lawyers for defending political prisoners and human rights campaigners during Raisi's term.
Raisi's victory raises concerns about the viability of talks to return both the United States and Iran to the 2015 Iran nuclear deal, from which the U.S. withdrew in 2018. In Vienna, talks are underway to bring both parties back to the table.
Raisi has taken a tough negotiating approach, asking that sanctions be eased before Iran makes any concessions. During his inaugural address, he reiterated this point.
"The sanctions must be lifted," Raisi said. "We will support any diplomatic plan that supports this goal."
Raisi also stated that he is aware of the many obstacles that lie ahead, including a struggling economy, and that he will work to enhance the quality of life for all Iranians.
He promised to be a true supporter of human rights in Iran and across the region.
