“We called in the Iranian ambassador to the foreign ministry to reiterate and reinforce this message and tell him what kind of measures we expect from Iran. On this and other issues,” Bildt said in an interview on Sveriges Radio on Tuesday.
The meeting took place on Monday, Bildt confirmed.
Iran has put around 110 people in the dock for their alleged role in protests against President Mahmoud Ahmadinejad since his re-election in June. Among them are a French lecturer and Iranian workers at the British and French embassies.
Sweden, which currently holds the European Union presidency, said in a statement at the weekend that the trials were an act against the entire 27-nation bloc.
Bildt said Sweden was prepared to take further action if Tehran does not immediately release the Frenchwoman and two local embassy employees.
“We are ready to take further steps if necessary. In consultation with the entire 27 EU member states, of course. But I think Iran is aware that we are prepared to take steps beyond what we have already done,” he said.
He would not disclose the type of action that could be taken.
“I don’t think one should go into that until the time has come. Right now we expect them to be released. If they are not released, we will see what happens then,” he added.