Recently, Bildt expressed disappointment that Iran was not included in the Syria peace talks in Montreaux.
The criticism of Blidt's trip is centered around Iran's human rights violations. Iran is second only to China in executions.
There was a protest outside the parliament in Stockholm today, where Bildt was speaking with journalists. "Before he travels to Iran, Bildt should demand that Iran's regime release all political prisoners, stop executions and also stop international terrorism," Mojtaba Gotbi, one of the demonstration's organizers, told Swedish Radio.