Donald Trump has accused Iran of working with with North Korea.
On Saturday (23 September), the US president tweeted: "Iran just test-fired a Ballistic Missile capable of reaching Israel.They are also working with North Korea.Not much of an agreement we have!"
He later issued a warning to Kim Jong-un, tweeting:
"Just heard Foreign Minister of North Korea speak at the UN. If he echoes thoughts of Little Rocket Man, they won't be around much longer!"
The statements came one day after Iranian media announced that the country had successfully tested its latest missile.
The Khorramshahr is a long-range ballistic missile that can carry multiple warheads. The launch of the missile was shown on state TV.
The missile was first displayed in the capital Tehran on Friday 22 September during military parades held to commemorate the Sacred Defence Week, which marks the anniversary of the 1980-1988 Iran-Iraq war.
The test is seen by some as a sign of defiance of Trump, who said Tehran was part of a "small group of rogue regimes" at the UN assembly in New York earlier in September.
The leader also called a nuclear deal the US – under the Barack Obama administration – and other countries reached with Iran in 2015 an "embarrassment for the US".
According to the deal – known as the Joint Comprehensive Plan of Action (JCPOA) – some sanctions against Iran were lifted as long as Tehran curbs its nuclear activity.
Trump has until mid-October to decide whether to stick to the deal. The leader said he has made his mind up, but did not add more details.
Iran's President Hassan Rouhani responded by saying that he does not think the US would pull out from the deal.
"We don't think Trump will walk out of the deal despite [his] rhetoric and propaganda," he said.
"If American officials think that they can pressure Iran by walking out of the deal, they are making a big mistake. Either the nuclear deal remains as it is or it will collapse," he added.
Rouhani was quoted by Press TV as saying during the military parade on Friday: "We will promote our defensive and military power as much as we deem necessary. We seek no one's permission to defend our land.
"Our armed forces and defence power have always been for strengthening peace and we have never utilised our defensive power for conquering a land but solely defending our own motherland," added the Iranian president.