Photo taken on July 19, 2017 shows a view of the historical city of Yazd in central Iran. UNESCO has added the historic city of Yazd to its list of world heritage sites on July 9, 2017. Photo:Xinhua

The United Nations Educational, Scientific and Cultural Organization (UNESCO) on Monday reiterated the importance of respecting international conventions on the protection of cultural property as tensions escalated in the Middle East.

US President Donald Trump warned Iran on Saturday that America has targeted 52 Iranian sites and Iran will be hit "very fast and very hard" if it attacks any American or US assets.

"We have targeted 52 Iranian sites, some at a very high level and important to Iran and Iranian culture," Trump tweeted.

"The Director General of UNESCO, Audrey Azoulay, on Monday received Ahmad Jalali, ambassador of the Islamic Republic of Iran, and discussed tensions in the Middle East with particular regard to heritage and culture," said the UNESCO in a press release.

Azoulay recalled the provisions of the 1954 Convention for the Protection of Cultural Property in the Event of Armed Conflict and the 1972 Convention concerning the Protection of the World Cultural and Natural Heritage -- two legal instruments that have been ratified by both the United States and Iran.

The 1972 convention stipulates, inter alia, that each State Party "undertakes not to take any deliberate measures which might damage directly or indirectly the cultural and natural heritage ... situated on the territory of other States Parties to this Convention," the UNESCO recalled.

Azoulay also recalled the terms of United Nations Security Council Resolution 2347 adopted unanimously in 2017, which condemns acts of destruction of cultural heritage, and stressed the universality of cultural and natural heritage as vectors of peace and dialogue between peoples, which the international community has a duty to protect and preserve for future generations.

Trump's threat came after a US airstrike near Baghdad International Airport on Friday killed Iranian Major General Qassem Soleimani, commander of the Quds Force of the Islamic Revolutionary Guards Corps, sparking outrage and vows of revenge from Tehran.