LONDON (Reuters) - Brexit negotiations this week have made progress in some areas but differences remain on important issues, Prime Minister Boris Johnson’s spokesman said on Friday. “We’ve had useful discussions this week and progress has been made in some areas. However, there still remain differences on some important issues,” the spokesman said. He said there were no plans for a formal statement from negotiators on Friday and that work towards a deal would continue next week. Britain was still committed to reaching a deal with the European Union, he added.