Demonstrators carry 'Death to America' banners and effigies of Trump during rallies held on the anniversary of the 1979 Islamic Revolution.
Iranians march in celebration for the 38th anniversary of the 1979 revolution to oust U.S.-backed shah.
Ayatollah Khamenei urged Iranians to take to the streets in a show of force against Trump.
'If we see smallest misstep from the enemies, our roaring missiles will fall on their heads,' Revolutionary Guard official says.
Jim Mattis spoke at a joint news conference in Tokyo with his Japanese counterpart, Tomomi Inada.
Some 22 Senators from both sides of the aisle send a letter voicing support for the bid to impose sanctions on Iran; eight signatories also supported the nuclear deal and include Clinton's former running mate Kaine.
Sanctions would be imposed in a manner that would not violate Iranian nuclear deal and will be imposed partly due to recent ballistic missile test.
Trump's comment comes day after his national security adviser put Tehran 'on notice.' Senior GOP congressmen support new sanctions.
In first public media appearance since taking office, Michael Flynn says 'Iran is feeling emboldened' as a result of the nuclear deal. U.S. threats 'useless,' Iran responds.
Tehran conducted two tests over the weekend: one on a long-range missile; the other on how the new U.S. president will react to its provocation.