"We can't go on forever with this question because it's affecting real people, real lives, real businesses right now because of the way the protocol is being interpreted," Johnson told reporters during a visit to the UK province to attend events marking the centenary of the partition of the island of Ireland and the formation of Northern Ireland.
As part of the Brexit agreement that came fully into force in January, there is no hard border between Northern Ireland and the Republic of Ireland, but under the protocol all goods and animal-based products coming from the rest of the British territories must be checked upon arrival in the UK province to see if the comply with EU sanitary regulations.
The UK government has argued that the protocol is not working, as it causes delays and interruptions to goods moving between Great Britain and Northern Ireland and irritates loyalists to the British crown who believe their place within the union could be affected.
Last week, the EU offered to cut checks on food, plants and animal products by 80% and reduce paperwork for transport companies in half, but London replied that there is still a big gap, so the whole protocol needed to be renegotiated.
"We need to flush it out pretty fast and we need to change the causes of the problem and not the symptoms, and I think we need to move pretty fast," Johnson insisted on Thursday.
Following EU’s offer to slash down customs check on goods crossing the Irish Sea into Northern Ireland, London and Brussels began negotiations that are due to last until mid-November.