At this time no one is able to say exactly what this may mean. It is usually taken in diplomatic circles as meaning there is a threat of military action. This is, what (?) day 12 of this brand new administration?
The Trump administration has said it was “officially putting Iran on notice” in reaction to an Iranian missile test and an attack on a Saudi warship by Iranian-backed Houthi rebels in Yemen but gave no details about how Washington intended to respond.
The threat was made on Wednesday by the national security adviser, Michael Flynn, in his first public statement since taking office.
Speaking in the White House briefing room, Flynn said a missile launch on Sunday and a Houthi attack on a Saudi frigate on Monday underlined Iran’s “destabilizing behavior across the Middle East.”.
https://www.theguardian.com/world/2017/feb/01/iran-trump-michael-flynn-on-notice
The Trump administration has said it was “officially putting Iran on notice” in reaction to an Iranian missile test and an attack on a Saudi warship by Iranian-backed Houthi rebels in Yemen but gave no details about how Washington intended to respond.
The threat was made on Wednesday by the national security adviser, Michael Flynn, in his first public statement since taking office.
Speaking in the White House briefing room, Flynn said a missile launch on Sunday and a Houthi attack on a Saudi frigate on Monday underlined Iran’s “destabilizing behavior across the Middle East.”.
https://www.theguardian.com/world/2017/feb/01/iran-trump-michael-flynn-on-notice