"Pleased to host Swiss FM @ignaziocassis on centennial of diplomatic relations—ties that endure based on mutual respect," Zarif tweeted.
"Excellent talks on bilateral, regional & global issues," he added.
"While appreciating Swiss efforts to mitigate US sabotage, a return to normal trade is global priority," he said.
Cassis started a three-day trip to Iran on Saturday by a visit to the ancient city of Isfahan where he toured the historical monuments of the city.
He is in Iran to mark the 100th anniversary of Switzerland’s diplomatic presence in the country.
Earlier in the day, Cassis said in a Twitter message that his meeting with Zarif was "fruitful".