Washington CNN  — 

As US officials were busy assessing Iran’s missile attacks in Iraq late Tuesday, messages began arriving from Iran saying one thing: We’re done.

Iran initiated contact through at least three back channels starting late Tuesday, including through Switzerland and other countries. There were “multiple messages and they were all the same,” a person familiar with the matter said. Iran wanted to convey their retaliatory action had ended – and was waiting to see how the US would respond.

The back-and-forth communication came as American officials were still determining the extent of the Iranian attacks, and were formulating plans for a response. In response, the US sought to communicate to Iran that its proxies in the region were of equal concern as the activities of the Iranian state, the person familiar said.

The National Security Council didn’t respond to a request for comment.

Multiple administration officials previously told CNN there is a growing belief among some Trump administration officials that Iran’s missiles intentionally missed areas populated by Americans when they targeted two Iraqi bases housing US troops early Wednesday local time. However, Army Gen. Mark Milley, the chairman of the Joint Chiefs of Staff, said it was his belief that Iran was trying to kill American military personnel in the attack.

Iran launched the attack in retaliation for the American strike that killed top Iranian Gen. Qasem Soleimani last week, further escalating tensions between the two countries. Officials have said there were no US casualties as a result of the attacks, though a full assessment is underway.

On Wednesday, President Donald Trump appeared to be positioning the US to de-escalate.

“Iran appears to be standing down, which is a good thing for all parties concerned and a very good thing for the world,” Trump said, striking a somber tone during his White House statement.

The President, though, offered very little room for Iran to maneuver, essentially sticking to a maximalist approach and demanding that any de-escalation happen on US terms. Reading carefully from teleprompters, Trump announced that his administration would once again slap Iran with more sanctions and demanded that US allies leave the nuclear deal so a new pact can be negotiated.

The US and Iran have exchanged recent messages through the Swiss diplomatic channel, according to the Swiss Ministry of Foreign Affairs and a source familiar with the channel. While the channel is always available and used regularly for consular issues, it’s use during a crisis situation is much more noteworthy, the source explained without specifying how recent messages were exchanged.

“Switzerland is deeply concerned about the heavy tensions between the U.S. and Iran and the latest cycle of violent confrontations in Iraq. We call on all sides to exercise maximum restraint and to avoid any further escalation. Switzerland stands ready to support initiatives of the international community that seek de-escalation in the region,” the statement said.

“The diplomatic communication channel between the U.S. and Iran that is provided by Switzerland in the framework of the protective power mandate continues to operate. Switzerland confirms that several messages were transmitted through this channel.”

CNN’s Kyle Atwood, Nicole Gaouette, Hamdi Alkhshali, Ryan Browne, Barbara Starr and Tamara Qiblawi contributed to this report.