After meeting with Mr. Pompeo, Federica Mogherini, the European Union's diplomatic chief, said she urged the US to "minimize and avoid escalating tensions".

Earlier the same day, Ms. Mogherini and the foreign ministers of Britain, France, and Germany (signatures to the Iranian nuclear agreement) held a special meeting to discuss the Iranian issue on the sidelines of the EU Ministerial Conference in Brussels. Mogherini affirmed that the EU fully supports the international nuclear deal with Tehran and wants to avoid further escalation of tension.

Meanwhile, British Foreign Secretary Jeremy Hunt warned that current tensions between the US and Iran could inadvertently trigger a military conflict. According to Hunt, it is time for all parties to be calm, understanding of each other, and make sure Iran does not return to the nuclear path.