The United States has announced new sanctions against Iran after its recent missile test, a move denounced by Tehran which said it would impose its own legal restrictions on American individuals and entities.
In a statement on its website on Friday, the US Treasury said it had added 13 Iranians and 12 companies, some of which are based in Lebanon, the United Arab Emirates and China, to its sanctions list.
"Iran's continued support for terrorism and development of its ballistic missile programme poses a threat to the region, to our partners worldwide, and to the United States," said John Smith, acting director of the Treasury's Office of Foreign Assets Control.
Among those sanctioned were companies, individuals, and brokers the US Treasury said support a trade network run by Iranian businessman Abdollah Asgharzadeh.
The Treasury said the businessman supported Shahid Hemmat Industrial Group, which, according to the US, is a subsidiary of an Iranian entity that runs Iran's ballistic missile programme.
The Treasury also sanctioned what it said was a Lebanon-based network run by the Islamic Revolutionary Guard Corps, the elite military body that is also powerful in Iranian politics and the economy.
Later on Friday, Iran's foreign ministry condemned the sanctions as illegal and vowed to reciprocate any measures taken against Tehran by the US.
"In retaliation for the US sanctions, Iran will impose legal restrictions on some American individuals and entities that were involved in helping and founding regional terrorist groups," state TV quoted a ministry statement as saying.
Al Jazeera's Dorsa Jabbari, reporting from Tehran, said the "list of individuals and entities will be released by the Iranian foreign ministry after it decides who will make the cut".
Iran last Sunday test-fired a medium-range missile, which the White House contends violated a UN Security Council resolution proscribing missiles that could carry a nuclear device.
Tehran has confirmed it tested a ballistic missile, but denied it was a breach of a 2015 nuclear deal with world powers or UN resolutions.
In a post on Twitter, Trump said his administration would not be as "kind" to Iran as the government of his predecessor, Barack Obama.
"Iran is playing with fire - they don't appreciate how 'kind' President Obama was to them. Not me!" Trump said.
The comment appeared to prompt a quick response from Mohammad Javad Zarif, Iran's foreign minister.
"Iran unmoved by threats as we derive security from our people. Will never initiate war, but we can only rely on our own means of defence," Zarif wrote also on Twitter.
Trita Parsi, president of the National Iranian American Council, said "all these new tensions that are emerging, and this war of words between the US and Iran in and of itself is endangering" the nuclear deal.
"The Trump administration has decided to really dial up this escalation without first establishing de-escalatory mechanisms - they don't have a direct dialogue with Iran in order to be able to calm things down once they believe they have achieved their objectives," he told Al Jazeera.
"So, if you only have an ability to dial it up, but not dial it now, that is what is most worrisome right now because it could, unfortunately, lead to a military confrontation."
Also on Friday, Iran said it had barred a US wrestling team from participating in the Freestyle World Cup competition in retaliation for an executive order by Trump banning visas for Iranians, Iran's state television reported.
On Wednesday, National Security Adviser Michael Flynn insisted the missile test was in defiance of UN Security Council Resolution 2231, which calls on Iran not to test missiles capable of delivering a nuclear weapon.
Bahram Ghasemi, Iran's foreign ministry spokesman, on Thursday called the claims "baseless, repetitive and provocative".
Source: Al Jazeera and news agencies