Cassis made the remarks in a meeting with Isfahan Governor General Abbas Rezayee late on Saturday.
"Switzerland-Iran relations date back to 100 years ago and they have continued since the late 19th century with the signing of the peace and trade agreement between Tehran and Bern," the Swiss foreign minister said during the meeting.
He, meantime, announced that Iran and Switzerland will celebrate the centenary of their joint diplomatic relations.
The Swiss foreign minister underlined that Bern is ready to increase the level of scientific and tourism cooperation with Tehran.
Noting that peace and trade are two important factors in the development of the two countries, Cassis said that "we are here today to say that Switzerland has always sought peace and tranquility".
Iranian Foreign Ministry spokesman Saeed Khatibzadeh said on Friday that the official schedule of the Swiss foreign minister will begin on Sunday in Tehran after a short stop in Isfahan, the most important of which is the meeting on the 100th anniversary of the start of relations between the two countries.
The Swiss foreign minister is slated to hold talks with Iranian President Hassan Rouhani and Foreign Minister Mohammad Javad Zarif on Sunday and Monday, Khatibzadeh said.