Rohani states that if Trump leaves the deal he will let nobody tell them anything about defending their country.
Trumps deadline about the deal is on twelve May. On this date Trump will have his decision on the Joint Comprehensive Plan of Action (JCPOA). The US president has to re-certify the deal every 3 months.
The pact is about lifting the sanctions on Iran. Iran had to decrease their uranium stockpile in return.
Israeli premier Netanyahu is also strongly against the pact made with Iran. In his opinion the making of this pact by Trumps predecessor Obama was a mistake