The Pentagon has announced the deployment of thousands of additional troops to “enhance the defence of Saudi Arabia”.
US Secretary of Defence Mark Esper says he has authorised the deployment of additional forces, including fighter jets and a defence system.
He said it was in response to “threats in the region”, amid efforts to protect the kingdom from “Iranian aggression”.
The move comes after an attack on Saudi Arabia’s oil facilities in September.
“Taken together with other deployments, this constitutes an additional 3,000 forces that have been extended or authorised within the last month,” Pentagon spokesman Jonathan Hoffman said.
The US has increased the deployment of forces in the region by 14,000 since May, according to CNN. Saudi Crown Prince Mohammed bin Salman had requested additional support, Mr Esper said.
The attack on Saudi oil facilities knocked out 5% of global oil supply and sent oil prices soaring. Both Saudi Arabia and the US blame Iran for the incident.
Mohammed bin Salman said: “If the world does not take a strong and firm action to deter Iran, we will see further escalations that will threaten world interests.”
Iran has denied allegations it was behind the attack.
However the leaders of France, Germany and the UK said in a joint statement that there was no other plausible explanation for the attacks.
Mr Esper told reporters at the Pentagon on Friday that the evidence from other recent attacks in the region proved Iran was to blame.
He said the “malign behaviour” was a part of the country’s “larger campaign to destabilise the Middle East and disrupt the global economy”.
“Iran’s attempts to use terror, intimidation and military force to advance its interests are inconsistent with international norms,” Mr Esper added.
“Saudi Arabia is a longstanding security partner in the Middle East and has asked for addition support to supplement their own defences and defend the international rules-based order.”