Iranian President Hassan Rouhani has called a decision by the United States to sanction Iran’s foreign minister “childish” amid rising tensions between the two countries.

In its latest move aimed at ratcheting up its “maximum pressure” campaign against Tehran, Washington on Wednesday said it was imposing sanctions on Mohammad Javad Zarif for acting on behalf of Iranian Supreme Leader Ayatollah Ali Khamenei – who is also subject to recently-imposed US sanctions.

In a televised address, Rouhani said the US was “resorting to childish behavior … They were claiming ever day ‘We want to talk, with no preconditions’ … and then they sanction the foreign minister.”

In his speech, Rouhani also accused the US of being “afraid” of Zarif, who recently gave a series of wide-ranging interviews to foreign media in New York.

In one of them, Javad Zarif hit back at US President Donald Trump’s call for new nuclear negotiations that encompass Iran’s ballistic missiles program and accused Washington of bringing the Middle East to the brink of “explosion” by selling arms to allies in the Gulf.