Prime Minister Mustafa al Kadhimi condemns the attack on the Syrian-Iraqi border, calling it a "blatant and unacceptable violation of Iraqi sovereignty and Iraqi national security".
Iraq has condemned overnight US air strikes against "facilities used by Iran-backed militia groups" on the Syrian-Iraqi border that reportedly killed at least seven people and sparked calls for revenge from Iraqi armed factions.
Prime Minister Mustafa al Kadhimi condemned the attack on Monday as a "blatant and unacceptable violation of Iraqi sovereignty and Iraqi national security".
"Iraq reiterates its refusal to be an arena for settling scores," Kadhimi added in a statement, urging all sides to avoid any further escalation.
The Iraqi government also said it would "study all legal options" to prevent such action being repeated.
The second such raid on pro-Iran targets since US President Joe Biden took office, described by the Pentagon as "retaliatory", led to fears of a new escalation between Tehran and Washington and came despite faltering efforts to revive a key deal over Iran's nuclear programme.
Reaction of Hashed
The Hashed, an Iraqi paramilitary alliance that includes several Iranian proxies and has become the main power broker in Baghdad, said the strikes killed four of its fighters in the Qaim region, some 13 kilometres away from the border.
The fighters were stationed there to prevent militants from infiltrating Iraq, the group said in a statement, denying that they had taken part in any attacks against US interests or personnel.
"We reserve the legal right to respond to these attacks and hold the perpetrators accountable on Iraqi soil," the Hashed said.
'Fully ready... to respond and take revenge'
Iraq's Hashd al Shaabi or Population Mobilisation Units (PMU) paramilitary alliance said that the air strikes "resulted in the martyrdom of a group of heroic fighters" and threatened revenge.
"...We are fully ready... to respond and take revenge," said PMU.
Sources from PMU told AFP news agency that four of the group's fighters had been killed in one raid in Iraq's vast western province of Al Anbar, a number also reported in Arab news.
US defence spokesman John Kirby said in a statement that three military facilities used by Iran-backed militia had been hit overnight Sunday to Monday – two in Syria and one in Iraq.
The targets – two in Syria, one in Iraq – were selected because "these facilities are utilised by Iran-backed militias that are engaged in unmanned aerial vehicle (UAV) attacks against US personnel and facilities in Iraq," Pentagon spokesperson Kirby said on Sunday.
The Pentagon said it had conducted retaliatory targeted air strikes against "facilities used by Iran-backed militia groups" on the Iraq-Syria border.
Syria's state-run SANA news agency said one child had been killed in the raid but gave few details.
US forces in Iraq have come under repeated attack in recent months, with the US consistently blaming Iran-linked Iraqi factions for rocket and other attacks against Iraqi installations housing its personnel.
I expect to be briefed tomorrow on the air strikes on the Iraq-Syria border. My statement tonight. pic.twitter.com/iSLBGUOAb2— Chris Murphy (@ChrisMurphyCT) June 28, 2021
US interests in Iraq, where 2,500 American troops are deployed as part of an international coalition to fight Daesh terror group, have been targeted in more than 40 attacks this year.
The vast majority have been bombs against logistics convoys, but rocket fire and drones packed with explosive have also been used in the assaults some of which were claimed by pro-Iran factions hoping to pressure Washington into withdrawing all its troops.
"Given the ongoing series of attacks by Iran-backed groups targeting US interests in Iraq, the president directed further military action to disrupt and deter such attacks," Kirby said.
"Specifically, the US strikes targeted operational and weapons storage facilities at two locations in Syria and one location in Iraq, both of which lie close to the border between those countries," he added.
Kataeb Hezbollah and Kataeb Sayyid al Shuhada, two Iraqi armed factions with close ties to Tehran, were among the "several Iran-backed militia groups" that had used the facilities, Kirby said.
Some of the militia groups that form the Hashed al Shaabi have been deployed in Syria over the years to support regime forces and to further Iran's interests in the country.
The latest US strikes come two days after the United States and France warned Iran that time was running out to return to a nuclear deal, voicing fears that Tehran's sensitive atomic activities could advance if talks drag on.
A return to the 2015 Iran accord has been a key Biden promise after the nuclear deal was trashed by his predecessor Donald Trump.
"We have a national interest in trying to put the nuclear problem back in the box that it was" under the deal, US Secretary of State Antony Blinken said.
The UN's nuclear watchdog said on Friday it had received no reply from Tehran over the possible extension of a temporary agreement covering inspections at Iranian nuclear facilities which expired on Thursday.
Announcement of the strikes came one day before Biden meets at the White House with Reuven Rivlin, president of Israel, Iran's arch foe.
The US just illegally bombed #Iraq & #Syria…again. Please stop saying you’re keeping our troops safe, if you want them safe, bring them home. Stop illegally occupying & bombing other countries & call it self-defense. pic.twitter.com/XgkCs2mVKu— Assal Rad (@AssalRad) June 28, 2021
US politicians alarmed
Some American politicians and experts, including US Senator Chris Murphy, expressed concern that the Biden administration went ahead with the attack without taking lawmakers into confidence.
"My concern is that the pace of activity directed at US forces and the repeated retaliatory strikes against Iranian proxy forces are starting to look like what would qualify as a pattern of hostilities under the War Powers Act," he tweeted.
The US attack comes just a day after the PMU – an Iran-backed umbrella organisation dominated by Iraqi Shia militias – showcased tanks and drones in a parade near Baghdad that was attended by senior officials.
READ MORE: US bombs Iranian militia facilities in Syria
Tit for tat
Since the start of the year, there have been more than 40 attacks against US forces in Iraq, where 2,500 American troops are deployed as part of an international coalition to fight the Daesh.
The vast majority have been bombs against logistics convoys, while 14 were rocket attacks, some of them claimed by pro-Iran factions that aim to pressure Washington into withdrawing all their troops.
The strikes come one day after Iraqi officials said three explosives-laden drones hit near the northern Iraqi city of Erbil, where the United States has a consulate.
In April, a drone packed with explosives hit the coalition's Iraq headquarters in the military part of the airport in Erbil.
The tactic poses a headache for the coalition, as drones can evade air defences.
"As demonstrated by this evening's strikes, President Biden has been clear that he will act to protect US personnel," Kirby said.