British Prime Minister Boris Johnson waves as he enters 10 Downing Street following his appointment by the Queen in London, Britain, 24 July 2019. Former London mayor and foreign secretary Boris Johnson is taking over the post after his election as party leader was announced the previous day. Theresa May stepped down as British Prime Minister following her resignation as Conservative Party leader on 07 June. EPA-EFE/NEIL HALL 
"The prime minister made clear that the UK will be leaving the EU on October 31, no matter what," said a statement from Johnson's office about a phone call between the two.
"The prime minister made clear that the government will approach any negotiations which take place with determination and energy and in a spirit of friendship, and that his clear preference is to leave the EU with a deal, but it must be one that abolishes the backstop." (Reporting by William James; editing by Guy Faulconbridge)