The announcement followed a call between president Joe Biden and Israel's prime minister Benjamin Netanyahu to discuss Israel's retaliation against Iran's 1 October attack when it rained nearly 200 missiles on Israel.
THAAD missile system: What is the defence system sent by US to Israel to assist in Middle East conflict?
Footage on social media showed what security sources later confirmed as the firing of a Terminal High Altitude Area Defense (THAAD) battery missile to intercept a Houthi attack from Yemen early on Friday.
A Hezbollah airstrike on an Israeli army base on Sunday killed at least four Israeli soldiers and injured dozens in one of the deadliest strikes in a year, underscoring the potential need for greater protection.
US soldiers have launched high-tech interceptor missiles from inside Israel for the first time since the system was deployed earlier this year.
