Iran's new president, Masoud Pezeshkian, was due in neighbouring Iraq on Wednesday as he moves to deepen already close ties on his first foreign visit since taking office.
Pezeshkian has vowed to make relations with neighbouring countries a priority as he seeks to ease Iran's international isolation and mitigate the impact of US-led sanctions on its economy.
His visit comes after Western powers on Tuesday announced fresh sanctions on Iran for supplying Russia with short-range missiles for use against Ukraine.
It also comes amid turmoil in the Middle East sparked by the war in Gaza, which has drawn in Iran-backed armed groups around the region and complicated Baghdad's ties with Washington.
On Tuesday night, an explosion was heard at a US-led anti-jihadist coalition's base at the Baghdad international airport, according to Iraqi security officials.
A spokesperson for the Iranian-backed Ketaeb Hezbollah (Hezbollah Brigades) in Iraq said the Tuesday night "attack" aimed to "disrupt the Iranian president's visit to Baghdad".
Ties between Iran and Iraq, both Shiite-majority countries, have grown closer since the US-led invasion of 2003 toppled the Sunni-dominated regime of Iraqi dictator Saddam Hussein.
"This trip will be an opportunity to promote and deepen the friendly and brotherly relations between the two countries in various fields," Iran's foreign ministry spokesman Nasser Kanani said this week.
Pezeshkian has directly linked shoring up ties to sanctions pressure.
"Relations with neighbouring countries... can neutralise a significant amount of pressure of the sanctions," he said last month.
Iran has suffered years of crippling Western sanctions, especially after its arch-foe the United States, under then-president Donald Trump, unilaterally abandoned a landmark nuclear deal between the Islamic republic and major powers in 2018.
Pezeshkian, who assumed the presidency in late July, has made the top diplomat who negotiated the 2015 deal, Mohammad Javad Zarif, his vice president for strategic affairs as part of his bid for a more open Iran.
Iran has become one of Iraq's leading trade partners, and wields considerable political influence in Baghdad, where its Iraqi allies dominate parliament and the current government.
Every year, millions of Iranian pilgrims visit Iraq's Shiite holy cities of Najaf and Karbala, and Pezeshkian will also visit the holy shrines there during his trip.
Non-oil trade between Iran and Iraq stood at nearly $5 billion over the five months from March 2024, Iranian media reported.
Iran also exports millions of cubic metres of gas a day to Iraq to fuel its power plants, under a regularly renewed waiver from US sanctions.
Iraq is billions of dollars in arrears on its payments for the imports, which cover 30 percent of its electricity needs.
In September last year, the two countries started construction of their first rail link -- a 32-kilometre (20-mile) line between Iraq's southern port city of Basra and the Shalamcheh border crossing, where it will join up with the Iranian rail network.
Washington still has around 2,500 troops in Iraq and 900 in neighbouring Syria as part of an international coalition against the Islamic State jihadist group.
Last winter, US-led coalition forces in both Iraq and Syria were targeted dozens of times with drones and rocket fire as violence related to the Israel-Hamas war in Gaza has drawn in Iran-backed armed groups across the Middle East.
The barrage of attacks triggered retaliatory US air strikes in both countries.
On Sunday, Iraqi Defence Minister Thabet al-Abbassi told pan-Arab television channel Al-Hadath that the US-led coalition would pull out of most of Iraq by September 2025 and the Kurdish autonomous region by September 2026.
Despite months of talks, the target dates have yet to be agreed between Baghdad and Washington.
Pezeshkian will also travel to the Kurdish regional capital Arbil for talks with Kurdish officials, Iran's official IRNA news agency said.
In March last year, Tehran signed a security agreement with the federal government in Baghdad after launching air strikes against bases of Iranian Kurdish rebel groups in the autonomous region.
They have since agreed to disarm the rebels and remove them from border areas.
Tehran accuses the rebels of smuggling in weapons from Iraq and of fomenting nationwide protests that erupted in 2022 following the death in custody of Iranian Kurd Mahsa Amini, detained for an alleged breach of Iran's strict dress code for women.
