Washington: The US has approved the long-stalled sale of fighter jets by Boeing Co. and Lockheed Martin Corp. to Gulf allies in deals valued at as much as $20 billion, according to people familiar with the decision.

The sales to Bahrain, Qatar and Kuwait can go ahead unless they are rejected by the US Congress. The Israeli government has used its influence to stall the sale of weapons to governments.

An “informal notification” sent to the House and Senate foreign affairs committees on Wednesday begins an initial review that could last as long as 40 days, according to the officials, who asked not to be identified in advance of a formal announcement that will come later. That notice will trigger an official 30-day review.

The aircraft sales will deliver on pledges by President Barack Obama and the Pentagon to bolster the weaponry of Sunni-led nations in the Middle East.

Those allies were left angry and uneasy after the US agreed to a deal with their regional rival, Iran, to ease international economic sanctions in exchange for curbs on its nuclear programme.

The notification to Congress says the potential sales include as many as 72 Boeing F-15 jets to Qatar and as many as 32 of the Chicago-based company’s F/A-18 E/F fighters to Kuwait, according to one of the people. Lockheed, based in Bethesda, Maryland, would be able to sell as many as 19 of its F-16s to Bahrain.

Qatar lodged its proposal in July 2013, and Kuwait made its request in April 2015. Bahrain’s is more recent.

The aircraft sales could be valued at as much as $12 billion for the planes, and $20 billion if spare parts, logistical support and munitions are included, according to Richard Abu Lafia, an aerospace analyst for the Teal Group in Fairfax, Virginia.

He underscored that the sales would help keep open assembly lines for older planes, such as the one in St. Louis where Boeing builds the F-15, as US purchases shift to Lockheed’s new F-35.

“These fourth-generation fighters have far more durability than anybody would have expected,” Abu Lafia said.

“It’s a solid win for both Boeing and St. Louis. The F-15 could conceivably live to see a half-century.”

Boeing was encouraged to finally see the sale progressing, said Scott Day, a company spokesman. “It’s nice to see the further movement on the fighter sales as they are part of the future of F-15, F/A-18 lines.”

Lockheed spokesman Bill Phelps said in an e-mail that “it would be inappropriate to comment on the details of ongoing government-to-government discussions between the US and Bahrain.”