Donald Trump, the US president-elect, has hired as a senior adviser a Republican national security veteran who first worked in the White House situation room under Richard Nixon.

As deputy national security adviser, 65-year-old Fox News commentator Kathleen Troia "KT" McFarland, will return once again to the executive mansion as number two to former general Mike Flynn.

"She has tremendous experience and innate talent that will complement the fantastic team we are assembling," Trump said, in a statement issued from his luxury Florida golf resort.