Israel was running low on Terminal High Altitude Area Defence (THAAD) interceptors as Iranian ballistic missiles slammed into Israeli cities in June.
The US asked Saudi Arabia to turn over interceptors to help the US ally in need. But Riyadh's response was "no", two US officials familiar with the talks told Middle East Eye.
"During the war, we asked everyone to donate," one official told MEE. "When that didn't work, we tried deal-making. It wasn't aimed at one country."
But Saudi Arabia was well placed to help Israel, and US officials have been keen to emphasise that Iran is a threat to them as well as Israel.
The US has already deployed air defence systems to the oil-rich Gulf state, which until recently was targeted by Houthi missile and drone attacks.
