State of the Union: Trump audience figures boast questioned

US President Donald Trump's boast that TV viewership for his speech to Congress this week was the "highest number in history" is under scrutiny.

Nielsen, which tracks US TV ratings, says Mr Trump's 45.6m viewers falls short of the numbers who tuned in to other State of the Union addresses.

Nielsen says Presidents Barack Obama, Bill Clinton and George W Bush all drew bigger ratings for their speeches.

Twitter said Mr Trump's speech attracted a record 4.5m tweets.