President Joe Biden informed Congress on Tuesday about his decision to deploy a ballistic missile defense system to Israel.
"I directed the deployment to Israel of a ballistic missile defense system and United States service members capable of operating it to defend against any further ballistic missile attacks while this defensive posture is deemed warranted," Biden said in a letter to congressional leadership.
He said the action is in line with his duty to protect Americans and interests abroad, and to uphold national security and foreign policy.
The Pentagon said earlier Tuesday that an advance team of US troops and the initial components for the Terminal High-Altitude Area Defense (THAAD) system arrived Monday in Israel.
Biden noted an Iran missile attack earlier this month on Israel and how the US contributed to a "historic defense" of Israel in the letter.
"Our shared success on October 1 included downing dozens of incoming Iranian weapons before they could harm civilians in Israel," he said.
Biden noted that recent adjustments to the US military posture were made to enhance force protection and provide greater support for Israel's defense.
The changes included the extension of the USS Abraham Lincoln Carrier Strike Group and the deployment of additional ballistic missile defense-capable destroyers, as well as fighter squadrons equipped with advanced aircraft like the F-35C Lightning II.
The US also deployed additional destroyers, including some that are ballistic missile defense-capable; the guided missile submarine USS Georgia, the USS Wasp Amphibious Ready Group/Marine Expeditionary Unit, multiple fighter and attack squadrons of Fourth and Fifth Generation Fighters including F-22, F-15E, and F-16, as well as A-10 Attack aircraft; and other forces, according to the letter.
The deployment of the air defense system comes as Israel vowed to strike Iran following Tehran's missile attack. Iran said it conducted that attack in retaliation for the assassinations of Hamas' former political leader in Tehran in July, and the killing of Hezbollah Secretary-General Hassan Nasrallah in Beirut last month.
Nearly 200 missiles were fired in the salvo, which struck several locations in Israel, including a military facility.
Iran has vowed to decisively respond to any further Israeli retaliation.
The exchanges of fire between Tel Aviv and Tehran have escalated after Israel bombed Iran's Embassy in Syria on April 1, killing senior military officials. Iran responded to that attack two weeks later by launching hundreds of drones and ballistic missiles at Israel.