"No one could imagine that a man in the United States would unilaterally grant a piece of land belonging to a certain nation to a usurper in violation of international law," Rouhani said in a meeting with a number of Iranian cabinet ministers and executive officials in Tehran on Tuesday, Presstv Reported.
He added that some "colonial powers" in the past carried out similar moves and donated a part of a country to another, "but such an action is unprecedented in the current century."
Breaking with decades of international consensus, Trump on Monday formally recognized Israeli "sovereignty" over the occupied Golan Heights, a border area the Tel Aviv regime seized from Syria in 1967.
Trump signed the proclamation as Israeli Prime Minister Benjamin Netanyahu and Trump's Jewish son-in-law and adviser Jared Kushner were standing at his side in the White House in Washington, DC.
Trump's move has not gone unnoticed and condemnations have been coming from around the world and prominent international rights groups.
Back in December 2018, the majority of the United Nations General Assembly adopted a resolution urging the Israeli regime to withdraw from the entirety of the Syrian Golan Heights.
The resolution, titled "The Syrian Golan," was adopted by a record vote of 99 in favor, 10 against and 66 abstentions. It declared that Israel’s controversial move to extend its laws, jurisdiction and administration on the occupied mountainous plateau is null and void.
Iranian Parliament Speaker Ali Larijani said on Monday that the US president has violated international regulations.
The top Iranian parliamentarian called on international bodies and the Inter-Parliamentary Union (IPU) to adopt serious measures in order to prevent another catastrophic development in the region.
Iranian Foreign Minister Mohammad Javad Zarif also expressed shock on Friday at the US president's move.
"All shocked by @realDonaldTrump continuing to try to give what is not his to racist Israel: first Al-Quds & now Golan" Zarif tweeted from Istanbul, Turkey, where he was attending an emergency meeting of the Organization of Islamic Cooperation (OIC).