The Trump administration on Friday imposed new sanctions against Iran, continuing what one observer describes as "an escalatory cycle with no clear exit."

Reuters wrote Friday, ahead of the official announcement:

The new sanctions, which are being taken under existing executive orders covering terrorism and weapons of mass destruction, may mark the opening shot in a more aggressive policy against Iran that Trump promised during the 2016 presidential campaign, the sources, who had knowledge of the administration's plans, said.

The Wall Street Journal adds that "Iran's government has repeatedly warned that any new sanctions imposed by the Trump administration will be viewed as a violation of the nuclear deal."

The sanctions are in response to Iran's test-firing a ballistic missile on Sunday.

Democracy Now! noted: "Many experts, as well as Iran's Foreign Ministry, say the missile test does not violate the terms of a 2015 U.N. Security Council resolution. The test also does not violate the terms of the landmark 2015 nuclear deal between Iran, the U.S. and other nations."

Trump National Security Advisor Michael Flynn, however, said Wednesday that the test was "provocative" and in defiance of the U.N. resolution, adding, "As of today, we are officially putting Iran on notice."

"I'd like to put as much toothpaste back in the tube as possible," added House Speaker Paul Ryan (R-Wis.).

"I think the last administration appeased Iran far too much," he said, and called for "a tough on-Iran policy."

Trump took to Twitter on Thursday to repeat the "on notice" phrase, and denounced, as he did on the campaign trail, the historic nuclear deal:

Iran has been formally PUT ON NOTICE for firing a ballistic missile.Should have been thankful for the terrible deal the U.S. made with them! — Donald J. Trump (@realDonaldTrump) February 2, 2017

He added in another tweet Friday:

Iran is playing with fire - they don't appreciate how "kind" President Obama was to them. Not me! SCROLL TO CONTINUE WITH CONTENT Never Miss a Beat. Get our best delivered to your inbox.





— Donald J. Trump (@realDonaldTrump) February 3, 2017

Iranian foreign minister Javad Zarif struck a different tone on Twitter, tweeting, apparently in response to Trump, that "Iran is unmoved by threats."

Iran unmoved by threats as we derive security from our people. We'll never initiate war, but we can only rely on our own means of defense. pic.twitter.com/TxlSEL8rjj — Javad Zarif (@JZarif) February 3, 2017

We will never use our weapons against anyone, except in self-defense. Let us see if any of those who complain can make the same statement. pic.twitter.com/xwGquvqLvb — Javad Zarif (@JZarif) February 3, 2017

The new sanctions, according to foreign policy expert Phyllis Bennis, "will further ratchet up tensions."

"There is a particular danger with a president unlikely to walk back his tweeted threats against Iran even if advisers warn him of the dire potential consequences—and with the National Security Council now seemingly run largely by White House strategic adviser and leading white supremacist and Islamophobic ideologue Steve Bannon," Bennis adds.

According to Trita Parsi, president of the National Iranian American Council, Flynn's comments "may have been bluster."

"But bluster without having established a channel for de-escalation is profoundly dangerous, and it is likely to increase rather than decrease the administration's challenges with Iran."

Parsi contrasts the tone set with Iran by the Trump administration to that set by the Obama administration, noting the key diplomatic relationship forged by former Secretary of State John Kerry with his Iranian counterpart, Zarif. And Bennis has also noted how the nuclear deal with Iran was an Obama administration foreign policy success made possible through the choice of diplomacy over militarism.

But Flynn, Parsi continued,