Iran will block American citizens from entering the country in “retaliation” for Donald Trump’s ban on travellers from seven majority-Muslim countries coming to the US, officials have said.

Tehran’s foreign ministry said in a statement it would enforce its own ban “until the offensive US limitations against Iranian nationals are lifted”.

The US ban is an “affront against the Muslim world”, the statement said, adding it would be a “great gift to extremists”.

Mr Trump’s policy of barring citizens from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen has caused outrage around the world.

The Republican billionaire signed an executive order on Friday that suspended travel visas for anyone from those seven “countries of particular concern” from entering the US for at least 90 days.

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The United Nations has condemned the ban and the International Organisation for Migration called on the new President’s administration to continue offering asylum to people fleeing war and persecution.

“The needs of refugees and migrants worldwide have never been greater and the US resettlement program is one of the most important in the world,” the two agencies said in a joint statement.

The Iranian Foreign ministry statement released on Saturday evening read: “While respecting the American people and distinguishing between them and the hostile policies of the U.S. government, Iran will implement the principle of reciprocity until the offensive U.S. limitations against Iranian nationals are lifted.

"The restrictions against travel by Muslims to America are an open affront against the Muslim world and the Iranian nation in particular and will be known as a great gift to extremists.”

Earlier on Saturday, Iran’s President Hassan Rouhani issued a thinly-veiled criticism of the US President.

Without naming Mr Trump, he said now was not the time to build barriers between nations.

Iranian president Hassan Rouhani speaking during a ceremony in Tehran, Iran, 28 January 2017 (EPA)

"Today is not the time to erect walls between nations. They have forgotten that the Berlin wall fell years ago," he said in a speech.

"To annul world trade accords does not help their economy and does not serve the development and blooming of the world economy.