U.S. President Donald Trumpinfo-icon's host of accusations levied against Iraninfo-icon in his United Nationsinfo-icon General Assembly speech on Tuesday was slammed by the Islamic Republic, who called the remarks "unworthy of a reply."

"Trump's ignorant hate speech belongs in medieval times - not the 21st century United Nations - unworthy of a reply," Iranian Foreign Minister Mohammad Javad Zarif tweeted on Tuesday.

"Fake empathy for Iranians fools no one," Zarif said.

Amidst threatening rhetoric and accusations singling out North Koreainfo-icon (DPRK), and Venezuelainfo-icon, Trump made the claim that Iran is a "corrupt dictatorship hiding behind the guise of a democracy."

Trump said that Iran, who has played a key role in supporting the Syrian government against the attacks of the Islamic Stateinfo-icon and other terror groups, have been "supporting terrorism."

"Trump's shameless and ignorant remarks, in which he ignored Iran's fight against terrorism, displays his lack of knowledge and unawareness," Iran's Foreign Minister Mohammad Javad Zarif was quoted as saying by Fars newsinfo-icon agency.

Trump slammed the 2015 Iran nuclear deal, which he called the "worst deal the United Statesinfo-icon has ever entered into," and said that Iran needed to stop its supposed "pursuit of death and destruction."

"The exiting of the United States from such an agreement would carry a high cost, meaning that subsequent to such an action by the United States of Americainfo-icon, no one will trust Americainfo-icon again," President Rouhani said in an interviewinfo-icon with NBC before Trump's address to the United Nations General Assembly.

Rouhani said that should the United States pull out of the nuclear agreement, Iran would consider going "back to previous activities," to develop peaceful nuclear technologyinfo-icon for energy production.

"So we will never go towards production of nuclear weaponsinfo-icon, just as in the past we never intended to go towards that path nor did we ever. It has always been peaceful," Rouhani affirmed.

U.S. Secretary of State Rex Tillerson said to reporters later that the only way the Iran nuclear deal would remain in place is if there were changes made to it. Iran has repeatedly rejected the idea that the deal could be renegotiated.

The Iranian nuclear deal, signed in 2015 between the Islamic Republic of Iran and the permanent member of the U.N. Security Council along with the European Unioninfo-icon, resulted in Iran giving up nuclear power development in exchange for the lifting of sanctions. Although it has been widely praised by the international community, the Trump administration has called for its destruction in order to take a "harder line" on Iran.