Iranian Foreign Minister Javad Zarif speaking at the Swiss Federal Institute of Technology in Lausanne, Switzerland in 2015.

Iran's Foreign Minister Mohammad Javad Zarif tweeted on Friday that the Islamic Republic was unmoved by U.S. threats following its missile test launch and that Tehran would never initiate war.



"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 defense," Zarif wrote.

U.S. President Donald Trump tweeted early on Friday that "Iran is playing with fire" and "they don't appreciate how 'kind' President Obama was to them. Not me!"

Trump said on Thursday that "nothing is off the table" in dealing with Iran following its launch of a ballistic missile. Fellow Republicans in Congress said they would back him up with new sanctions.

Zarif said Iran had no intention to use its military might against any country, except in self-defence.

"We will never use our weapons against anyone, except in self-defence. Let us see if any of those who complain can make the same statement," he tweeted.

Iran said on Thursday it would not yield to "useless" U.S. threats from "an inexperienced person" over its missile programme.