Swedish Foreign Minister Carl Bildt is due in Iran for a four-day visit aimed at bolstering Iran's interim nuclear deal with the West.
Bildt's press officer, Erik Zsiga, called the visit an "opportunity for us to weigh in so that the temporary deal becomes permanent."
A six-month deal putting temporary curbs on Iran's nuclear program in exchange for an easing of sanctions was agreed to in November 2013 and came into effect on January 20.
Talks on a long-term pact, which would replace the interim deal, are due to begin on February 18 in Vienna.
The talks bring together Iran with the five veto-holding members of the UN Security Council -- Britain, China, France, Russia, and the United States -- plus Germany.
Bildt wrote on his blog that he was traveling to Iran "to try to reach out a hand in support of change and cooperation."
Despite "deep disagreements" with the regime, he said there was "great awareness of the importance of the country and respect for its cultural and historic tradition."
In addition to the nuclear dispute, Iran is also at loggerheads with most of the West over the Syrian conflict. Tehran supports the regime of President Bashar al-Assad against the Western and Persian Gulf monarchy-backed opposition.
Bildt is starting his visit in Isfahan, where Iran has a uranium-conversion facility.
Speaking on February 2 to RFE/RL's Radio Farda at the Munich Security Conference, Bildt expressed optimism that Western relations with Iran could improve if the nuclear negotiations were successful.
"There are clearly great expectations among many people that there would be further changes [in Iran]. But I think a lot of that is dependent on the nuclear negotiations with the West," Bildt said.
"If the [talks] succeed, I think, there could also be an opening for further changes in Iran in other areas."
Bildt also welcomed the new tone that has been set by President Hassan Rohani, who is considered a relative moderate in comparison to his more hard-line predecessor, Mahmud Ahmadinejad.
But he said the result of Rohani's new approach remained unclear.
"I clearly see goodwill on behalf of, at the moment, President Rohani and [Iranian] Foreign Minister [Mohammad Javad Zarif]. But Iran is a complex society, and we know that there are other forces [in the country], as well. So it remains to be seen," he said.
At the Munich conference, Zarif held what are considered rare private talks with U.S. Secretary of State John Kerry.
A U.S. State Department official said Kerry stressed to Zarif the importance of both sides negotiating in good faith and Iran abiding by its commitments under the interim deal.
The UN's nuclear watchdog agency, the International Atomic Energy Agency, is continuing to probe possible military aspects of Iran's nuclear program.
Iran has always denied any effort to develop a nuclear weapon.
With reporting by AFP and Reuters