Tehran, Jan 17 (IANS): Iran has warned the US to stop "illegal actions" taken against its diplomats on American soil, Foreign Affairs Ministry spokesman Saeed Khatibzadeh confirmed.

"Iran has officially warned the US that it will sue it before the International Court of Justice if it does not stop its illegal actions against Iranian diplomats in international organisations," Xinhua news agency quoted Khatibzadeh as saying on Saturday.

The spokesman noted that an official warning has been delivered to US authorities through the Foreign Interests Section of the Swiss Embassy in Tehran.

Washington should refrain from taking "illegal action" against Iranian representatives before international organisations such as the UN, the World Bank and the International Monetary Fund, that have their siege on American soil, Khatibzadeh stated.

For a long time, he carried on, the US government has been creating "illegal constraints" for Iranian diplomats and their families, disrupting their work and that of other countries.

Despite its commitment as host to several international organisations, Khatibzadeh went on to say, Washington has "never been a proper host", and has consistently harassed diplomats, their families, and children coming from countries it has problems with.

Also on Saturday, the Iranian President's Chief of Staff Mahmoud Vaezi slammed the latest sanctions imposed by Washington against Tehran as a mere "show" and a sign of the "evil nature" of the outgoing American President Donald Trump's administration.

"The recent US sanctions, while nothing more than a show, are another sign of the evil (nature) of Trump's criminal administration - a bankrupt government that even in its final days cannot put aside its hostility towards Iranians," Vaezi said in a social media post.

He added in the post that it is "surprising" that, despite their "deep brazen enmity," US officials "still claim that they stand by the Iranian people".