The US government by maintaining its unilateral approach and economic terrorism against Iranian nation, through an unusual step against diplomatic norm and international law, on July 30 put name of Dr Javad Zarif, Foreign Minister of the Islamic Republic of Iran, in the sanctions list of US Treasury Department. The Trump administration for last one year has adopted a unilateral approach by committing illegal methods not only against Islamic Republic of Iran but also diplomacy and multilateralism. Unilateral withdrawal from Joint Comprehensive Plan of Action (JCPOA), which was concluded after one decade of negotiations, imposing sanctions against Islamic Revolutionary Guards Corps (IRGC), an official defense force of the Islamic Republic of Iran, imposing sanctions on Supreme Leader of the Islamic Republic of Iran, and now illegal ban on Foreign Minister of the Islamic Republic of Iran after imposing some restrictions on his presence in the United Nations General Assembly session on July 12, 2019, are only some evident cases of illegal behaviour of the US government in violation of the international laws. The decision of banning Foreign Minister is in violation of international obligations of US, including established international rules, principles and laws, obligations under UN Charter, The Vienna Convention on Diplomatic Relations (1961) and the UN Headquarters Agreement (1947). According to Article IV Section 11 of the UN Headquarters Agreement, “The Federal state or local authorities of the United States shall not impose any impediments to transit to or from the headquarters district of representative of members or officials of the United Nations, performing missions for the United Nations”. Moreover, according to the Geneva Convention, diplomatic representatives enjoy inviolable immunity against any type of action of the host government. US officials claim that banning of Foreign Minister is meant to exert maximum pressure on the Islamic Republic of Iran to change stance of its government, but as the Minister has not any asset or bank account outside the country, in fact these sanctions are more symbolic rather than a practical step and show the weakness of US against logic and arguments of the diplomatic apparatus of the Islamic Republic of Iran. Dr Zarif is not only a Foreign Minster but also a voice for the rightfulness of the Islamic Republic of Iran in diplomatic language. The US sanctions on Dr Zarif have proven that he has a profound influence on public opinion globally and especially on the US people’s opinion about the untruthful approaches and policies of their leaders. So, when someone is not capable of facing and defeating his rival, then he tries to remove the rival by using unethical methods. Putting up name of Foreign Minister of Iran in the sanctions list of the US Treasury Department is an illegal and unprecedented step to prevent essential duties of Ministry of Foreign Affairs of an independent and sovereign state and member of UN, which creates impediment in way of establishing of official communication of the government with other governments and international organisations. The US government through this step has targeted entirety of foreign relations of Iran in interaction with the world and has proved that against its apparent claims, it does not truly willing to talk and negotiate with the Islamic Republic of Iran. Banning of Dr Zarif is not his personal ban rather is being considered imposition of sanctions against the very notion of ‘diplomacy’ at the global level. This action is unacceptable legally, normally and morally and leads toward closing down of diplomatic way, channels of discussions and resorting to peaceful means to settle international disputes. Finally this action provides basis for escalations in the region and the whole world. Not showing appropriate response to this illegal step may lead to a dangerous procedure. This is the first time that one government systematically put officials and official institutions of another state under sanctions. However, during tenure of Donald Trump, sanctions have become a routine weapon to put pressure on other countries. Officials and institutions of 37 countries of the world are under the US sanctions. In fact, after attempts to stop oil exports of Iran, banning of the officials of Iran, now it is the last arrow in the hand of US through which it has blindly tried to target political system of Iran from its forehead but has hit the heart of diplomacy. US as an imperialistic power is showing last teeth to make its opponent kneel down. Recent US sanctions against head of diplomatic apparatus of a sovereign state is in stark contrast to the spirit of diplomacy and is in contrast to the claims by US officials regarding inviting Iran for negotiations without any pre-conditions. As sanctions against Iranian nation and preventing them from access to food, medicines and interests gained from oil sale is in contradiction to colorful and false claims of US in defense of human rights and democracy. Also, freezing the assets of Iran and preventing the country from exporting oil and other resources has unrivaled contradiction with hollow slogan of US about global free trade. The US has repeatedly proven that it can take any measure and does not spare any step in violation of any rule of international relations and law to fulfill its self-claimed interests. Instead of counting on trans-regional powers, now is the critical moment for us to come together to solve regional issues and defend international law, peace, security and regional development with unity and convergence. The writer is the Ambassador of the Islamic Republic of Iran to Pakistan