The US State Department has approved the sale of thousands of smart bombs worth a total of $1.29 billion to Saudi Arabia to help replenish supplies used in its battle against insurgents in Yemen and air strikes against Islamic State in Syria, US officials familiar with the deal said on Monday.

The Pentagon's Defense Security Cooperation Agency (DSCA), which facilitates foreign arms sales, notified lawmakers on Friday that the sales had been approved, the sources said.

The lawmakers now have 30 days to block the sale, although such action is rare since deals are carefully vetted before any formal notification.

The proposed sale includes thousands of Paveway II, BLU-117 and other smart bombs, as well as thousands of Joint Direct Attack Munitions kits to turn older bombs into precision-guided weapons using GPS signals.

The sales reflect President Barack Obama's pledge to bolster US military support for Saudi Arabia and other Sunni allies in the Gulf Cooperation Council after his administration brokered a nuclear deal with their Shiite rival Iran.

The weapons are made by Boeing Company and Raytheon, but the DSCA told lawmakers the prime contractors would be determined by a competition.

The sale was first reported by Bloomberg.

Saudi Arabia, one of the largest buyers of US weapons, was approved in September for a potential second sale of 600 Patriot-PAC-3 air defense missiles made by Lockheed Martin Corp , a deal valued at $5.4 billion.

Last month, the US government also approved the sale to Saudi Arabia of up to four Littoral Combat Ships made by Lockheed for $11.25 billion.-Reuters