Thaad, or the Terminal High Altitude Area Defence system, is a critical part of the US military's layered air defense systems.
"The Thaad system is in place," Mr Austin said, speaking to reporters before his arrival in Ukraine on Oct 21, Reuters reported.
He declined to say whether it was operational, but added, "We have the ability to put it into operation very quickly and we're on pace with our expectations."
In response to a question regarding President Joe Biden's statements about knowing when and how the Zionist regime would act against Iran, Austin stated, "It's hard to say exactly what that (Israel's) strike will look like".
"We're going to do - continue to do - everything we can ... to dial down the tensions and hopefully get both parties to begin to de-escalate. So, we'll see what happens," he said.
Iran launched a retaliatory attack on occupied Palestine with a barrage of its homegrown missiles on October 1, with the Islamic Revolutionary Guard Corps (IRGC) saying that 90% of them hit the targets.
The operation came in response to the regime’s assassinations of Hamas’ chief Ismail Haniyeh, Hezbollah’s leader Sayyed Hassan Nasrallah, and IRGC commander Abbas Nilforooshan.
Iranian Defense Minister says that the target of Iran's retaliatory attack on Israel was an intelligence headquarters and 3 of the Tel Aviv regime's military bases.
“Operation True Promise II was carried out with more than 90% success and was fully in line with international law,” he said.
No civilian sites were among Iran's targets, he stressed.
Iranian officials have strongly warned the Zionists about responding to Iran's operation, saying that the country would target the infrastructures in occupied Palestine in that case.
SD/