LONDON, (Reuters) – The British Prime Minister Boris Johnson stated that he prefers a negotiated solution to post-Brexit Northern Ireland trade issues. However, if the government decides to escalate their dispute with Brussels, it will so in a responsible manner.

In recent weeks, relations between London and Brussels have been strained after Britain protested the 2020 deal, which threatened to activate Article 16 – potentially leading to trade war.

London and the European Union eventually agreed to increase their efforts to resolve the issues arising from the Northern Ireland Protocol. This was after Brussels had welcomed Britain’s “change of tone”.

Johnson spoke late Monday about United Nations COP26 climate summit. He said he’d rather find a negotiated resolution to problems caused by the Northern Ireland Protocol. It still appears possible.

“But if we do invoke Article 16 – which by the way is a perfectly legitimate part of that Protocol – we will do so reasonably and appropriately, because we believe it is the only way left to protect the territorial integrity of our country, and meet our obligations to the people of Northern Ireland under the Belfast (Good Friday) Agreement,” he said.

Brussels will need to determine how it will respond if Britain invokes Article 16. Its response will probably depend on London’s attempts to make the mechanism work as a starting point for a larger renegotiation.

Maros Séfcovic of the European Commission stated Monday that while he believed Britain and Europe could reach an agreement on post-Brexit trade arrangements, he still had concerns about London’s rhetoric and actions.