After saying he was in talks with the UK, Mr Trump - who pulled America out of the Iran Nuclear Deal last year - said: "This only goes to show what I'm saying about Iran. Trouble. Nothing but trouble."
The events come a day after Donald Trump said the US Navy "destroyed" an Iranian drone in the Strait of Hormuz, a claim Iran denied.
In the midst of the international tensions, which have escalated since Iran shot down a US drone in June, the president posted a tweet about his efforts to release imprisoned rapper A$AP Rocky.
The American star is currently in a Swedish prison while police finish their investigation into a fight that took place in downtown Stockholm.
Tensions high as Trump approves new Iran sanctions: In pictures
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“Just spoke to Kanye West about his friend A$AP Rocky's incarceration”, Mr Trump posted online. “I will be calling the very talented Prime Minister of Sweden to see what we can do about helping A$AP Rocky. So many people would like to see this quickly resolved!”
Earlier in the day, the feud between Donald Trump and Congresswoman Ilhan Omar raged on.
The president has faced increasing criticism over his racist attacks of the Somali-born Democrat.
Despite saying he disapproved of the “send her back” chants at a North Carolina rally, Donald Trump today praised the rally attendees as "incredible patriots," and said Representative Omar is “a disgrace to our country.”
The latest political figure to defend the freshman representative is Angela Merkel.
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The German Chancellor said Mr Trump's racist comments about Ilhan Omar, Alexandria Ocasio-Cortez, Ayanna Pressley and Rashida Tlaib undermine America's strength" and that she stands in "solidarity" with the congresswomen.
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