The event, attended by Iraqi Prime Minister Mustafa al-Kadhimi, marked seven years since the Popular Mobilisation Forces (PMF) were formed to fight the Sunni Muslim extremist Islamic State group.
"I esteem your sacrifices, and the sacrifices of the Iraqi armed forces" in fighting Islamic State, Kadhimi said, warning against any "sedition" within the PMF, but without elaborating.
The PMF's establishment created a state-sanctioned umbrella organization of mostly Shi'ite militias backed by Iran.
The Iran-aligned factions, which are the most powerful in the PMF, have since Islamic State's defeat in 2017 expanded their military, political and economic power and attacked bases housing the 2,500 remaining U.S. forces in Iraq.