The Defense Department said the deployment would involve one battery of the surface-to-air missiles, along with four Sentinel radars used for air and missile defense systems.

In addition, two more Patriot batteries and one THAAD ballistic missile interception system are being readied in case a decision is made to also supply them to the Saudis, Pentagon spokesman Jonathan Hoffman said.

"This deployment will augment the kingdom's air and missile defense of critical military and civilian infrastructure," he said.

It comes "in light of recent attacks on the Kingdom of Saudi Arabia," he said.

"It is important to note these steps are a demonstration of our commitment to regional partners, and the security and stability in the Middle East," he added.

"Other countries have called out Iranian misadventures in the region, and we look for them to contribute assets in an international effort to reinforce Saudi Arabia's defense."

The US has pointed to Iran being behind the combination drone and cruise missile attacks on September 14 which heavily damaged two Saudi oil installations, forcing the key oil supplier to slash output.

Iran has denied responsibility, and President Hassan Rouhani on Thursday challenged the US and others to provide evidence to back up their accusations