Belgian foreign minister Hadja Lahbib is facing calls for resignation after granting visas to delegations from Iranian and Russian cities to attend a mayors convention in Brussels last week.

Lahbib is under scrutiny for having approved visas for citizens from two countries under international sanctions and only three weeks after Belgian Olivier Vandecasteele was released from an Iranian jail.

Vandecasteele, 42, was arrested on a visit to Iran in February 2022 and sentenced in January to 40 years in prison and 74 lashes on trumped-up charges including spying.

He was freed last month in a prisoner swap with an Iranian diplomat who had been convicted in Belgium for a terror bombing plot in France.

The "Brussels Urban Summit," which took place last week, saw the mayors of more than 300 international cities including Tehran, and also members of the European Commission and the European Parliament, gathering to discuss challenges cities are facing.

Tehran's mayor, Alireza Zakani is a hardliner who was a leader in the Basij student militia.

State secretary for external relations & foreign trade of the Brussels government Pascal Smet resigned on Sunday over the all-expenses paid trip.

Belgo-Iranian lawmaker Darya Safai, from opposition party N-VA, said on Monday the party is asking for Lahbib's resignation.

"We need a minister who accepts her responsibility," Safai told Matin Premiere radio.

"The pending question is why did she agree to give these visas? Why only three weeks after the release of Olivier Vandecasteele, she accepts that terrorists come to Brussels? And why must the name of Belgium always be sullied by foreign relations which it cannot manage to control?" she said.

Belgian lawmakers will meet on June 21 to discuss the issue.

Based on Reporting by Reuters