The Pentagon described the deployment as “moderate”, adding that forces will be defensive in nature. It added forces will primarily focus on air and missile defences. Sky news reported US troops and military equipment will also be sent to the neighbouring United Arab Emirates, a Saudi Arabian ally.
US Marine General Joseph Dunford, chairman of the Joint Chiefs of Staff, said personnel would not be in the thousands but he was not more specific.
Defence Secretary Mark Esper said troops and equipment were being sent in response to a request from the Saudis and UAE for help improving their air and missile defences.
Mr Esper claimed sending in troops was a first step but he is not ruling out additional future moves.
President Trump claimed restraint “shows far more strength” as he outlined new sanctions on the Iranian central bank.
READ MORE: Iran threat latest: Trump sanctions Iranian National Bank after Saudi
General Dunford said military experts were still considering the best way to help the Saudis defend themselves and highlighted the difficulty in combating a drone attack.
He commented: “No single system is going to be able to defend against a threat like that, but a layered system of defensive capabilities would mitigate the risk of swarms of drones or other attacks that may come from Iran.”
The Abaqaiq facility and the Khurais oil field were attacked in the early hours of last Saturday.
The attacks caused a reduction of more than half in Saudi Arabia’s daily oil experts, more than five percent of the world’s daily production.
Houthi rebels, backed by Iran, initially said they were responsible for the attack.
In recent days, the finger has been pointed directly at Iran.
Iran denies any involvement in the attack on the oil facilities.
Tensions between the US and Tehran surged after Trump withdrew the US from the Iran nuclear deal last year.