The British government summoned Iran's most senior diplomat in London on Monday to protest at what it said were serious threats against journalists living in Britain.
On Saturday, a London-based television station critical of the Iranian government said it was moving its live broadcasting studios to the United States following threats it faced in Britain.
"I am appalled by the Iranian regime's continuing threats to the lives of UK-based journalists and have today summoned its representative to make clear this will not be tolerated," Foreign Secretary James Cleverly said in a statement.
The ministry said the Iranian Charge d'Affaires had been told in a meeting with British officials that Britain would not accept such threats to life and media freedom.
Separately, the government imposed sanctions on three Iranian judges, three members of Iran's Islamic Revolutionary Guard Corps and two regional governors over what it said were human rights violations.
