President Donald Trump was set to be deposed Friday in a defamation lawsuit he filed against the British Broadcasting Corporation, but his lawyers recently canceled the session and said he is unavailable through at least mid-December, according to a court filing. "The President is no longer available for his deposition on October 16 due to other matters of national importance," Trump's attorneys told lawyers for the BBC late last month, the network's attorneys said in motion Tuesday. The BBC is asking a judge to force Trump to set a firm date to submit to questioning in the case.