US President Donald Trump has tweeted that "Iran is playing with fire" and "they don't appreciate how kind President Obama was to them. Not me!"
Trump plans to impose sanctions on several Iranian entities, seeking to ratchet up pressure on Tehran while crafting a broader strategy to counter what he sees as its destabilising behaviour, sources familiar with the matter said.
Iran's decision to test-fire a ballistic missile on Sunday helped trigger Trump's decision, which could be announced as early as Friday, they said.
Iran's Foreign Minister Mohammad Javad Zarif tweeted that the Islamic Republic is unmoved by US threats following its missile test launch and Tehran will 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 defence," Zarif tweeted.
