New Jersey Governor Chris Christie said "there is no justification" for the behaviour of his former aide Bridget Kelly's over the bridge scandal.
Christie, a possible Republican White House contender, told a news conference, "There is no justification for ever lying to a governor or a person in authority in this Government".
More top news
Scientists claim bubbling magma is behind the 'man in the moon' image rather than an asteroid strike
Our Political Editor Tom Bradby has been tackling readers' questions about David Cameron's conference speech.
Author Stephen Fry has said he regrets his 'pathetic' 15-year addiction to cocaine after writing about it in his new autobiography.