US 'close to completing' $100 billion Saudi arms deal
According to the official, the US could boost the kingdom's defence capabilities with a package that may surpass $300 billion over a decade.
The US will still however ensure that Israel maintains its qualitative edge over its neighbours, the official added.
"We are in the final stages of a series of deals," the official said.
The multi-billion dollar arms package is being prepared ahead of US President Donald Trump's visit to Riyadh on May 19.
Washington is Riyadh's main supplier of arms and military equipment, with the ultra-conservative kingdom having purchased tens of billions of dollars in fighter jets and command and control systems in recent years.
"It's good for the American economy but it will also be good in terms of building a capability that is appropriate for the challenges of the region," the anonymous official said.
On his maiden foreign trip as US president, Trump is expected to discuss the fight against the Islamic State group, the war in Yemen and threats to maritime shipping in the Red Sea with Gulf leaders.
Discussions about safe havens for Syrian refugees, or 'de-escalation zones', will also be feature prominently during the president's trip.
As well as visiting Saudi Arabia, Trump's trip will include stops to Israel, Brussels, the Vatican and Sicily for a NATO Group of Seven summit.