The United States will send an aircraft carrier and a bomber task force to the Middle East in response to “troubling and escalatory indications and warnings” from Iran , national security adviser John Bolton announced on Sunday.

NEW: US is deploying an aircraft carrier and a bomber task force to the Middle East in response to "a number of troubling and escalatory indications and warnings" by Iran and "to send a clear and unmistakable message to the Iranian regime," NSA Bolton says in statement. pic.twitter.com/gonfifAzyO

Bolton, who is known for his hawkish stance on Iran, did not specify what “warnings” the United States was responding to; however, a U.S. official with knowledge of the situation told CNN that threats had been made against “both U.S. maritime and land-based forces in the Middle East.”

Although there has been no indication that “any action by Iran is imminent,” the deployments are meant as a deterrent, the official told the news network.

Secretary of State Mike Pompeo confirmed on Sunday that the U.S. had seen “escalatory actions from the Iranians,” AP reported. He refused to elaborate on what these actions entailed, yet insisted that “we have good reason to want to communicate clearly about how the Iranians should understand how we will respond to actions they may take.”