WASHINGTON – The Defense Department notified Congress on Wednesday that it plans to sell Saudi Arabia as much as $60 billion worth of weapons to help confront threats from Iran and violent regional extremists.

The proposed weapons sale, which may be the largest to another country in U.S. history if all purchases are made, includes Boeing F-15 fighter jets, attack helicopters and satellite-guided bombs, according to notices sent to Congress. It also contains helicopters made by United Technologies and advanced radar from Raytheon.

Congress has 30 days, or until Nov. 20, to stop the sale before the Defense Department and companies proceed into more detailed talks with Saudi Arabia. Congress will review the proposed sale during its scheduled Nov. 15-19 post-election session.

The proposed sale “represents a powerful symbol of the robust strategic relationship between the United States and Saudi Arabia,” said Colin Kahl, deputy assistant secretary of defense for the Middle East. The Saudis instead could have bought equipment from Britain, France, Russia or China, he said.

The sale reflects a common view of threats facing Saudi Arabia and the United States that undermine stability in the Middle East. The Obama administration has failed to persuade Iran to curb its missile and nuclear programs, and militant groups, including those linked to al-Qaida, continue to operate in the region.

Saudi Arabia’s last significant U.S. weapons purchase was for 72 F-15s in 1992, a transaction valued at as much as $9 billion.