According to Khamenai.ir the website associated with the office of the supreme leader of Iran, Ayatollah Khamenai, they have published the following in response to the limited attack threat made by US President Donald Trump. 

We have shown a degree of restraint in response to the enemy’s provocations and attacks so far, but this time it will be different; a regional war awaits the aggressors, their allies, and those who host them. In such a war, the previous red lines will fundamentally change, and the battlefield will be broader than before. 

The list of targets will expand, and if the soil of Iran and the lives of its people are subjected to harm or American aggression, then American interests and lives will not be safe anywhere.