The Pentagon warned Thursday that the Iran-backed Kataeb Hezbollah group that stormed the US embassy in Baghdad would carry out more attacks on US facilities -- and would regret it.\r\n\u201cThe provocative behavior has been out there for months... So do I think they may do something? Yes. And they will likely regret it,\u201d Defense Secretary Mark Esper told reporters.\r\n\u201cWe are prepared to exercise self-defense, and we are prepared to deter further bad behavior from these groups, all of which are sponsored, directed and resourced by Iran.\u201d\r\nEsper said there were \u201csome indications out there\u201d that groups may be planning additional attacks, and that the US would respond accordingly.\r\n\u201cIf we get word of attacks or some type of indication, we will take preemptive action as well to protect American forces, to protect American lives,\u201d he said.\r\nThe Pentagon\u00a0ordered hundreds of rapid-response troops to the Gulf region\u00a0Tuesday after Iraqi protesters\u00a0stormed the normally highly-protected US embassy\u00a0compound in Baghdad, breaching its outer wall while chanting \u201cDeath to America!\u201d\r\nThe protestors, many from Kataeb Hezbollah, were angered by weekend air strikes by US forces that killed 25 of their supporters, said by Washington to be retaliation for rocket attacks on December 27 that killed a US civilian contractor.\r\nJoint Chiefs Chairman General Mark Milley said Iran had been behind a \u201csustained campaign\u201d to provoke the United States since at least October.\r\n\u201cWe know that the campaign has increased in tempo and intensity,\u201d he said.\r\n\u201cWe know that the intent of this last attack was in fact to kill American soldiers, sailors and the Marine... 31 rockets aren\u2019t designed as a warning shot. That\u2019s designed to inflict damage and kill.\u201d\r\nEsper said the reinforcements, sent to Kuwait, would allow the Pentagon to be prepared \u201cfor any contingency.\u201d\r\n\u201cThe game has changed and we\u2019re prepared to do what is necessary to defend our personnel, and our interests and our partners in the region,\u201d he said.