The Pentagon’s plan to sell and lease U.S. Apache gunships is worth more than $6 billion. (Alexander Nemenov/AFP/Getty Images)

The Pentagon formally notified Congress on Monday that it intends to sell and lease attack helicopters to Iraq, deals worth more than $6 billion that had been snarled by concerns U.S. lawmakers raised about potential misuse of the aircraft.

Sen. Robert Menendez (D-N.J.), who chairs the Foreign Relations Committee, notified the State Department late Friday that he had lifted his objection to the deal after administration officials convinced him that U.S. personnel would be able to ensure that the Apache helicopters are not used to target minority populations or political rivals of the government in Baghdad, a Senate aide said Monday.

Iraqi officials hope the Apaches — speedy and versatile aircraft armed with highly precise missiles — will be a game-changer in their fight against the Iraqi al-Qaeda-linked group, which has made a stunning comeback over the past year.

Al-Qaeda militants recently secured footholds in Ramadi and Fallujah, two important cities in western Iraq, and have established sophisticated training camps in nearby desert areas.

The first of the six leased Apaches could arrive in Baghdad as early as this summer, said the Senate staffer, who spoke on the condition of anonymity to describe a weapons deal that has not been finalized. Over the next three years, Baghdad will acquire another 24 helicopters.

“This proposed sale supports the strategic interests of the United States by providing Iraq with a critical capability to protect itself from terrorist and conventional threats, to enhance the protection of key oil infrastructure and platforms and to reinforce Iraqi sovereignty,” the Defense Security Cooperation Agency, which handles foreign military sales, said in a statement issued Monday.

U.S. officials have watched with alarm as Iraq’s al-Qaeda affiliate has grown in strength and absorbed cells of jihadists fighting to topple the Syrian government across the border.

American estimates of the size of the Iraqi al-Qaeda group range between 3,000 and 7,000 fighters, a senior U.S. defense official said in a recent interview, speaking on the condition of anonymity to discuss internal assessments.

“They’re getting precipitously stronger,” said the official, who noted that the group is focused on regional political objectives and has not displayed an interest in attacking the United States. “The money involved, the complexity of attacks, the geography is pretty impressive.”

The Apaches are a key piece of a large arsenal of weapons and vehicles Iraq is trying to buy from the United States. The Pentagon had informally notified Congress last year that Iraq was interested in the helicopters.

Menendez was among several lawmakers who voiced concern about the Apache deal last year. He and other U.S. officials worry that Washington could come to regret backing Iraq’s security forces because the government in Baghdad has often used them to crack down on members of the country’s Sunni minority. Iraq’s Sunni deputy prime minister echoed those concerns during a recent visit to Washington, arguing that the solution to Iraq’s crisis is a power-sharing compromise — not merely more weapons.

Menendez asked the State Department last summer whether the United States would have a mechanism to ensure that the aircraft weren’t used improperly. He received a “substantive” response in recent weeks that satisfied him, the Senate aide said.

The sale will require the assignment of three U.S. government personnel and about 200 contractors in Iraq.