According to Pakistan, Munir will participate "in the ongoing mediation efforts", but the Iranian side emphasizes that the visit does not necessarily mean that "we have reached a turning point or a decisive moment".
On the contrary, Foreign Ministry spokesman Esmaeil Baqaei states that the differences of opinion with the US are "deep and far-reaching."
A delegation from Qatar also arrived in Iran on Friday.
In recent days, many countries, both regional and non-regional, have tried to help end the war, but Pakistan remains the official mediator, Esmaeil Baqaei said.
US Secretary of State Marco Rubio spoke vaguely in Helsingborg on Friday about continued "small progress" in attempts to reach an agreement.
