In this photo dated Monday Oct. 14, 2019 people walk past pro-Brexit graffiti in West Belfast Northern Ireland. Fears about a return to the violence that killed more than 3,500 people over three decades have made Northern Ireland the biggest hurdle for U.K. and EU officials who are trying to hammer out a Brexit divorce deal. (AP Photo/Peter Morrison)
In this photo dated Monday Oct. 14, 2019 people walk past pro-Brexit graffiti in West Belfast Northern Ireland. Fears about a return to the violence that killed more than 3,500 people over three decadShow more

Boris Johnson vows to scale 'final summit' in pursuit of Brexit breakthrough