Iran's President Ebrahim Raisi has met with convicted terrorist Assadollah Assadi, who was released from Belgium in May in exchange for a Belgian hostage in Tehran.

A court in Belgium had sentenced Assadi to a 20-year prison term after being found guilty of involvement in a plot to orchestrate an attack on an Iranian opposition event in 2018 near Paris. However, he was released from prison and returned to Iran on May 26 as part of a mediated exchange carried out with the assistance of Oman.

In return for Assadi's release, Iran released Belgian aid worker Olivier Vandecasteele, who had been incarcerated in Tehran for nearly 15 months.

Despite the long trial in Belgium that led to Assadi's conviction, Iran claimed that he was innocent and treated him as a hero upon his return. Assadi was a diplomat in Iran's embassy in Austria and according to evidence submitted during his trial, he used his diplomatic status as a cover to organize the bomb plot.

The president's office reported on Saturday that during the meeting on Friday, President Raisi said, "The proponents of human rights have once again demonstrated their disregard for established legal frameworks." He further claimed that these countries “had violated international norms and principles” by undermining the diplomatic immunity of the Iranian diplomat.

The prisoner exchange marked the culmination of extensive political debates in Belgium, particularly within the nation's parliament. In January, Vandecasteele, aged 42, had been sentenced to 40 years in prison and 74 lashes on charges of "espionage," a verdict that both his family and Belgian authorities criticized as "unfair."

Since May, Oman-mediated negotiations have led to the release of six European citizens held in Iran, while several are still held hostage.