A U.S. Air Force F-15 fighter jet does a low-level flyby in eastern Afghanistan in this January 1, 2009 file photo. The Obama administration will soon notify Congress of an arms sale to Saudi Arabia worth up to $60 billion, U.S. officials said on Monday, a potentially record-breaking deal that may help counter Iran's growing regional muscle.

A U.S. Air Force F-15 fighter jet, like the ones to be sold to the Saudi Air Force. Photo: Reuters

THE US government has announced a deal with Saudi Arabia, agreeing to sell F-15 fighter jets valued at nearly $US30 billion to the Royal Saudi Air Force.

The agreement, and the government's parallel plan to press ahead with a nearly $US11 billion arms deal for Iraq, despite rising political tensions there, is evidence of its determination to project US military influence in the oil-rich Persian Gulf, which is shadowed by a threat from Iran.

Although the White House said the deal had not been accelerated to respond to threats by Iranian officials in recent days to shut off the Strait of Hormuz, its timing is laden with significance, as tensions with Iran have deepened and the US has withdrawn its last soldiers from Iraq.

''This sale will send a strong message to countries in the region that the United States is committed to stability in the gulf and the broader Middle East,'' said Andrew Shapiro, the Assistant Secretary of State for Political-Military Affairs. ''It will enhance Saudi Arabia's ability to deter and defend against external threats to its sovereignty.''

The agreement also suggests that the US and Saudi Arabia have moved beyond a falling-out over the uprisings in the Arab world. Although the two countries continued to differ on how to handle the popular revolts in the region, US and Saudi officials said, the disagreement had not fractured a strategic alliance based on a common concern over Iran.

Saudi Arabia has long been a foe of Iran, with relations souring further last northern autumn after the US broke up what it said was an Iranian-backed plot to kill the Saudi ambassador to Washington. Iran has denied the accusations.

''When you look at the size of this package, what does it tell you about US-Saudi relations?'' said a senior Saudi official, who spoke anonymously because he was not authorised to speak publicly.

''It says it's very strong and very solid. Any disagreements from time to time don't affect the core relationship.''

The weapons package is remarkable, both for its size and technical sophistication. Under the terms of the $US29.4 billion ($A28.9 billion) agreement, Saudi Arabia will get 84 Boeing F-15SA jets and upgrades to 70 F-15s, with new munitions and spare parts. It will also get help with training, logistics and maintenance.

The new F-15s, which will be delivered in 2015, are among the most capable and versatile fighter jets in the world. They will come with the latest air-to-air missiles and precision-guided air-to-ground missiles, enabling them to strike ships and radar facilities day or night and in any weather.

Although Mr Shapiro and other officials said the planes were intended to help Saudi Arabia protect its sovereignty, military analysts said they would be effective against Iranian planes and ships anywhere in the Persian Gulf.

The planes are part of a 10-year, $US60 billion weapons package for Saudi Arabia that Congress approved last year.

NEW YORK TIMES