Qassemi made the remark in response to "incorrect and unfounded" claims made by US President Donald Trump against Iran in an interview on Tuesday with four members of The Wall Street Journal’s White House team in the Oval Office.
In his interview, Trump claimed that Iran is "not the same country" since he took office and after he "terminated" the landmark nuclear agreement, officially known as the Joint Comprehensive Plan of Action (JCPOA), signed between Iran and the P5+1 group of countries in 2015, Press TV reported.
Qassemi dismissed the US president's claims and said, "It seems that Trump does not have necessary information about the conditions in the region, its history and characteristics of its peoples as well as the developments in the recent years."
"Iran is undoubtedly the same country with all its features. [It] is exactly the same country which has been before Trump's presidency without any change in its regional policies," he added.
The US president announced in May that Washington was pulling out of the nuclear agreement, which lifted nuclear-related sanctions against Tehran in exchange for restrictions on Tehran's nuclear program.
A first round of American sanctions took effect in August, targeting Iran's access to the US dollar, metals trading, coal, industrial software, and auto sector. A second round, forthcoming on November 4, will be targeting Iran's energy sector and financial transactions.
The Iranian spokesperson emphasized that Tehran's regional policies are to fight extremism and terrorism, make efforts to establish peace and security in the region and help boost development and growth in all countries in the Middle East.
He also pointed to Iran's presence in Syria and said it came at the request of the Syrian government in order to help fight terrorism and give advisory support to the Arab country.
"Iran has no operative military forces in any country; although Iran's advisory forces have played a fundamental and important role in helping the Syrian government in the fight against terrorism," Qassemi pointed out.
Qassemi also said Iran would make efforts to defend itself in the face of ill-wishers and opponents based on its national interests and in accordance with all international regulations.
Iran would stand by all regional governments and nations who are interested in cooperation with the Islamic Republic in order to stabilize peace and security in the region and fight terrorism and extremism, Qassemi added.
The Iranian spokesman urged the US president to learn about "the real issues in the region" given the ongoing developments and to review the history once again.