Hossein Dehghan dimmed hopes for a thaw in US-Iran relations.
Lebanon's Hezbollah have been accused of hiding missiles in Beirut schools.
Ambassador Shea has been outspoken in her criticism of Lebanese militant group Hezbollah.
Macron has been spearheading international efforts to rescue Lebanon from its deepest crisis since the 1975-1990 civil war.
After a blast of historic proportions at Beirut's port last year, Lebanon only escaped a second chemical inferno by chance, the German company clearing the dockside has said.
Comment: While Lokman Slim's killing may not lead to accountability, it will certainly not silence his comrades, writes Cilina Nasser.
Qatar's foreign minister pledged support for Lebanon throughout rebuilding Beirut but said there is no initiative for reconciliation.
Iran has asked the UN to intercede on its behalf after allegations of Israeli escalation of hostilities.
Beirut is struggling under the weight of another coronavirus surge.
Since the August blast and a massive fire at the port weeks later, authorities have been concerned about dangerous material still at the facility.