Iran test-fired a medium-range ballistic missile late Wednesday that traveled 1,000 kilometers from its southern launch point into northern Iran, according to a US official with direct knowledge of the event.
The launch of the Shahab-3 missile did not pose a threat to shipping or US bases, the official said, and remained inside Iran for the duration of its flight. Nevertheless, it served as a signal to the US and Europe and could serve to further increase tensions in the region.
The missile was launched from Iran's southeastern coastline along the Gulf of Oman and landed in northern Iran, the official said.
While analysts said Iran's missile test might be destabilizing given the volatile situation in the Persian Gulf, it doesn't violate any United Nations resolutions — which has been a source of frustration to critics of the Iran deal.
UN Security Council Resolution 2231 , which endorsed the Iran nuclear deal, "called upon" Iran to refrain from activities related to ballistic missiles designed to be capable of delivering nuclear weapons.
"The missile test is inconsistent with the Security Council resolution, and certainly destabilizing, but not a violation," said Mary Kaszynski, deputy policy director of the Ploughshares Fund, an anti-nuclear foundation.
Kaszynski said that "unless the specific test is a significant technological advancement, this is really more about political messaging and part of the cycle of escalation between the Iranian regime and the Trump administration."
Wednesday's test follows a pointed exchange between Iran and the US over missiles and may be meant to underscore that Iran will not negotiate over its missile program.
Secretary of State Michael Pompeo has said that Iran must end missile testing as one of 12 conditions he has laid out for an end to the maximum pressure campaign the Trump administration implemented after it left the Iran nuclear deal in May 2018.
Trump administration officials have repeatedly criticized the 2015 Iran nuclear deal because it did not include Tehran's missile program or what it calls Iran's malign activity in the region. They say they want both included in a future agreement.
The Obama administration and other parties to the deal -- France, the UK, Germany, the EU, Russia and China -- say that it was necessary to focus the pact on nuclear activity in order to reach an agreement, which took years to negotiate.
In a July 15 interview with NBC, Iranian Foreign Minister Javad Zarif that if the Trump administration wants to talk about Iran's missiles, it should first "stop selling all these weapons, including missiles, to our region," possibly a reference to arms sales to Saudi Arabia and the United Arab Emirates.
Speaking to reporters Tuesday at a White House Cabinet meeting the next day, Trump and Pompeo seemed to interpret that as a new sign of Tehran's willingness to negotiate.
Trump said that in addition to his belief that Iran must not develop a nuclear weapon, "they can't be testing ballistic missiles, which right now under that agreement [the 2015 Iran nuclear deal] ... they would be able to do."
But Iran has long said it won't negotiate over its ballistic missile program, which is controlled by Revolutionary Guard Corps who report to Supreme Leader Ayatollah Ali Khamenei.
After the Cabinet meeting and media reports suggesting Tehran might be willing to negotiate over its missile program, Iran's spokesman at the UN, Alireza Miryousefi, made clear that Zarif was only making a hypothetical point.
"Iran's missiles are absolutely and under no condition negotiable with anyone or any country, period," Miryousefi tweeted.
Iran's Wednesday missile test comes amid a widening crisis between Iran and Western powers, and friction between the US and its allies over how to deal with Iran.
Last week, the Islamic Revolutionary Guard Corps seized a British tanker in the Strait of Hormuz, one of the world's most vital shipping routes, saying Iran had been "violating international regulations." The seizure was seen as retaliation for the British navy impounding an Iranian tanker off Gibraltar just days earlier.
In June, Iran shot down an American drone, claiming it was intruding on its territory, throwing the two countries into a military standoff.
More recently, the US and Europe have been at odds over plans to secure shipping in the Persian Gulf.
The US had been urging regional and international parties to take part in Operation Sentinel, which Washington casts as an effort to secure freedom of navigation in the Persian Gulf, the Strait of Hormuz and the Gulf of Oman, crucial waterways for the passage of global oil supplies.
The UK has announced its Navy will accompany British ships where possible and that it will participate in a European-led effort to provide security to shipping through the Gulf and the Strait of Hormuz, a strategic chokepoint controlled by Iran through which 20% of the world's oil supply passes.