A THAAD missile defense system and two additional Patriot missile batteries are prepared to go if needed, the Pentagon said.
"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," Pentagon spokesman Jonathan Hoffman said.
Esper said the deployment was a first step toward addressing Iran's increasingly violent acts in the region -- including this month's drone attack on Saudi Arabian oil facilities -- and he called on other nations to step up and condemn the attacks.
Iran-backed Houthi rebels in Yemen claimed responsibility for the Sept. 14 attack on the world's largest oil processing plant and a major oil field, but the U.S. and Saudi Arabia blamed Iran directly. Iran has denied involvement in the attack.
“It is clear […] that the weapons used were Iranian-produced and were not launched from Yemen,” Esper said Friday, noting that all signs indicate “Iran was responsible for the attack."
The purpose of deploying troops and resources is to "send a clear message that the United States supports our partners" and provide a "free flow of resources," Esper said.
The U.S. calls on other countries to also "stand up and condemn the attacks," as well as contribute capabilities, the secretary said.
Fox News' Lucas Tomlinson and The Associated Press contributed to this report.