IRBIL, Iraq — One of Iraq’s most powerful Iran-backed armed groups said Tuesday it would begin putting its weapons under government control, a major step in the new government’s effort to bring militias that have long operated on their own under state command.

Asaib Ahl al-Haq said it had formed a committee to oversee the move, including an inventory of its fighters, weapons and equipment, and to coordinate with the commander-in-chief of the armed forces. The group cast the decision as a response to calls by Iraq’s top Shiite religious authority and the Iran-aligned Coordination Framework, the largest bloc in Parliament that dominates Iraqi politics.

The war in the Middle East has exposed the fragility of Iraq’s state institutions and their limited ability to restrain these groups. A parallel confrontation between Washington and the militias has deepened the crisis, with factions acting as an extension of Iran’s regional campaign and escalating attacks on U.S. assets in Iraq before a tenuous ceasefire deal was reached in April.

The first significant move came a week ago, when the influential Shiite cleric Muqtada al-Sadr said his Saraya al-Salam militia, also known as the Peace Brigades, would split from his political movement and integrate into state institutions.

Under pressure from Washington, Prime Minister Ali al-Zaidi has been working to assert state authority over weapons. Al-Zaidi, a 40-year-old banker sworn in last month has made a state monopoly on arms a centerpiece of his program. The Trump administration has warned against any government influenced by Iran-linked factions and tied defense cooperation and funding to efforts to curb them.

Many Iran-backed militias are funded through the Iraqi state budget and embedded within the security apparatus, although not under the government’s control. This has drawn criticism from the United States and other countries that have borne the brunt of their attacks and say Baghdad has failed to take a tougher stance.

Several armed factions aligned with Iraq’s Coordination Framework have taken a different stance on efforts to bring weapons under state control. Two important groups, Kataib Hezbollah and Harakat al-Nujaba, have rejected disarmament, tying the issue to Iraq’s sovereignty and the presence of foreign troops.

Kataib Hezbollah welcomed moves by other factions to place weapons under state authority but said its own armed activity will continue as part of what it describes as “resistance work.” In a recent statement attributed to its Abu Mujahid al-Assaf social media channel??? TV channel? Telegram channel? Something else altogether?, the group said it would offer coordination with the Popular Mobilization Forces rather than surrendering arms.

The PMF, a state-backed umbrella of mostly Shiite armed groups, was formed in 2014 to fight the Islamic State group. Many of its groups still keep their own command and ties to Iran.