The latest contracts would raise to nearly $5 billion the value of a series of US arms sales to Iraq that have been sent to Congress over the past two weeks.
Congress has 30 days to act to block the sales, but otherwise they would have its tacit approval.
The biggest of the contracts notified on Monday was worth an estimated $2.4 billion.
It involves the sale of 681 Stinger anti-aircraft missiles and 40 truck-mounted launchers, as well as three Hawk anti-aircraft batteries with 216 Hawk missiles.
"This capability will provide Iraq with the ability to contribute to regional air defenses and reduce its vulnerability to air attacks and also enhance interoperability between the government of Iraq, the US, and other allies," the Pentagon said in a statement.
Iraq's lack of control over its airspace was one reason why the Pentagon argued that US forces should be kept in the country beyond 2011. In the end, the United States pulled out all its troops because Baghdad refused to grant them legal immunity.
The second contract, worth $339 million, involves the sale of 19 mobile radio systems and 10 microwave radio systems.
On July 25, the Defense Security and Cooperation Agency sent Congress three other proposed arms sales to Iraq worth $2 billion.
The package included the sale of 12 Bell 412 EP transport helicopters, and 50 Stryker armored vehicles equipped for nuclear, radiological, biological and chemical warfare.
Iraq previously ordered 36 F-16 fighter aircraft at the end of 2011.
Iraq's Prime Minister Nuri al-Maliki last year called on the United States to accelerate the delivery of arms for Iraqi troops, after signing a contract with Moscow to supply Iraq with $4.2 billion in arms.
The deal with Moscow fell through, however, because of suspicions of corruption.