Updated

The deputy director-general of Britain's MI5 spy agency has been named as the new chief of the government surveillance agency known as GCHQ.

Foreign Secretary Boris Johnson said Monday that Jeremy Fleming will become director of GCHQ. Johnson said Fleming has worked for two decades to help keep Britain safe from attack.

Fleming will succeed Robert Hannigan, who said in January he was stepping down as director for personal reasons.

GCHQ has been dragged into the controversy surrounding President Donald Trump's assertion that he had been a surveillance target at the direction of former President Barack Obama.

In a rare public statement, GCHQ last week rejected the claim that it had been involved as "nonsense" and "utterly ridiculous."

GCHQ plays an important role in the effort to intercept extremists' communications.