Leaders joke behind Trump's back at NATO 70th summit

Nato's 70th anniversary summit has been overshadowed by rows, including a spat over a recording of Canadian Prime Minister Justin Trudeau appearing to mock US President Donald Trump. Leaders of the world's most powerful defence alliance have increasingly struggled to project a united front. Defence spending and relations between Turkey and other member states were key issues looming over this summit among its 29 member alliance. Joining us now from London is our correspondent Olly Barratt.