The United States has vowed to help Iraq combat terror groups as mounting attacks claimed more lives ahead of talks between Iraqi Prime Minister Nuri al-Maliki and President Barack Obama.
Maliki's visit to Washington comes as his country is wracked by the worst unrest since 2008, and just a few weeks before the two-year anniversary of the withdrawal of American troops from Iraq.
Only hours before he met with Vice President Joe Biden for talks focusing heavily on security, three suicide bombings killed 14 Iraqi security forces, the deadliest in a series of attacks which have left 35 dead in two days.
Vice President Biden reiterated the US commitment to equip Iraqis to fight al-Qaeda, and Maliki made clear he views the US as "Iraq's security partner of choice", the White House said in a statement, calling the talks "friendly" and "constructive".
Unrest in Iraq has reached a level unseen since 2008 and killed more than 5400 people this year, with Iraqi authorities failing to curb daily attacks despite a swathe of operations and tightened security measures.
Although Iraq has already received some $US14 billion ($A14.8 billion) in US support, Maliki has said he intends to press Washington for more help when he meets with Obama on Friday at the White House.
"We do want to help the Iraqis develop the capability to target these networks effectively and precisely," a senior administration official told reporters after the two-hour breakfast meeting.
"It is a fact now that al-Qaeda has a presence in western Iraq, and it has a presence in terms of camps and facilities and staging areas that the Iraqi forces are unable to target effectively," the US official said, asking not to be named.
Many militants are slipping into Iraq from Syria, armed with heavy weapons, and targeting Iraqi forces as well as civilian Shi'ite areas. "They're targeting playgrounds, weddings, funerals, and this is having a devastating psychological impact," the official said.
In a bid to clamp down on the attacks, the US was "increasing expert cooperation with the Iraqis... to help the Iraqis have a better vision of what they face so they can target it effectively."
US officials have also already notified Congress of plans to sell Iraq "a major air defence system which allows them for the first time to take sovereign control of their air space, which right now they don't have," the official said.
The Washington Post reported that Baghdad was hoping to buy US-made Apache helicopters.
Iraq has also ordered dozens of F-16 warplanes from the US for delivery in late 2014, the US official said, confirming Baghdad had deposited some $US650 million ($A687 million) as a downpayment.
Maliki met later on Wednesday with US lawmakers in a bid to persuade them to approve the arms deals, a day after a group of US senators accused him in a letter to Obama of contributing to an alarming slide back into a sectarian war.
Representative Ed Royce, the chairman of the House Foreign Affairs committee, said they discussed "a range of critical issues" including Iran and the September attack on a camp in Iraq, housing members of an Iranian opposition group.
"I urged the prime minister to do more to reconcile with his political opponents on key issues in order to marginalise the terrorists and militants who threaten to draw Iraq into another deadly civil war by exploiting these disagreements," Royce said in a statement.
