Zarif welcomed Ri and a team of officials at the Foreign Ministry in Tehran, but no statement was made to reporters.
Ri is on a two-day visit to Tehran; he was due to meet with President Hassan Rouhani on Wednesday. His trip came on the same day that the U.S. restored sanctions on the Islamic Republic.
Ri was present alongside a high-level Iranian delegation at a meeting of the Non-Aligned Movement in Baku, Azerbaijan, in April.
A North Korean delegation also attended President Hassan Rouhani's inauguration in August 2017.