Bildt's press officer Erik Zsiga told AFP on Wednesday that the foreign minister, one of Europe's most experienced and well-connected diplomats, will be in Iran from Monday through Thursday next week.
News of Bildt's trip came after the announcement on January 20th of a six-month deal putting temporary curbs on Iran's nuclear programme came into effect following years of fruitless negotiations.
"The visit is an opportunity for us to weigh in so that the temporary deal becomes permanent," Zsiga said.
The agreement is the first step to reach a global accord that will certify that Tehran's nuclear ambitions have peaceful purposes.
Bildt wrote on his blog that he will be travelling to Iran "to try to reach out a hand in support of change and cooperation".
"I am surprised by the strong support for this initiative," he wrote, but did not mention where the support came from.
"Even though we often have deep disagreements with the regime in Tehran, there is great awareness of the importance of the country and respect for its cultural and historic tradition," he added.
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In mid-January, EU foreign policy chief Catherine Ashton, who was invited by Tehran, said she intended to visit the Iranian capital "in the course of the next weeks", but no specific date has been revealed since.
Iran and global powers are expected to meet in New York in mid-February to discuss an agreement on Tehran's nuclear plans.