sunday times he again praised the foreign secretary boris johnson on his bid to become prime minister. he criticized the outgoing prime minister theresa may and her negotiations on brexit and as a matter of advice, mr. trump insisted he would never pay the $50 billion price tag to leave the european union. listen. well, if i were them, i wouldn't pay $50 billion. that's a big number. i wouldn't pay $50 billion. that's me. i'm only saying this from my stand point, i would not pay that. that's a tremendous number. >> some of these candidates are saying they would walk away if they don't get what they want. others are disagreeing. presumably you think -- >> if they don't get what they want, i would walk away, yes. this is their decision. you're just asking my opinion. i would not -- if you don't get the deal you want, if you don't get a fair deal, when you walk away. >> let's go live to london, our phil black following the story. phil, it is common knowledge the president of the united states