Iran's foreign minister said on Friday that his country will "never initiate a war", despite facing threats, in reference to a series of US warnings over its testing of missiles.
Tehran was "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," Mohammad Javad Zarif said on his official Twitter account.
"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," the Iranian minister wrote.
His posts came after US President Donald Trump used his Twitter account to accuse Iran of "playing with fire".
On Thursday, Trump said "nothing is off the table" when a journalist asked him whether military action against Iran was an option.
That came only hours after Trump tweeted that he was putting Iran "on notice" following Sunday's missile test.
Iran has confirmed it tested a ballistic missile, but denied that it violated the terms of a UN Security Council resolution on its nuclear programme.
It denounced the Trump administration's warnings as "baseless" and "provocative".
On Friday, Iran's foreign ministry said it had refused visas for US athletes due to compete in a wrestling tournament in the country in response to Trump's travel ban on seven mainly Muslim nations.
"Considering the policies adopted by the new US administration, the foreign ministry was inevitably forced to refuse travel by the US wrestling team to Iran," ministry spokesman Bahram Ghasemi was quoted as saying by the official IRNA news agency.
The team had been due to take part in the event in western Iran on February 16 and 17.
Trump signed an executive order a week ago barring entry of all refugees to the US for 120 days, Syrian refugees indefinitely and blocking citizens of Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen from entry for 90 days.
The order, which caused mayhem worldwide and has been met with legal challenges, was later clarified to say that green card holders were not targeted by the ban.