British Prime Minister Rishi Sunak on Saturday sought to dampen optimism about an imminent settlement in the dispute over post-Brexit trade rules for Northern Ireland that has brought political turmoil to the region and clouded relations with the European Union. A recent flurry of meetings and diplomatic activity, including his late-night dash to Belfast on Thursday night, has yet to yield an agreement, Sunak said during a question-and-answer session following his speech at a security conference in Munich.