Britain on Thursday pledged £400 million ($532 million, 439-million-euro) to bolster Northern Ireland against Brexit trade disruption from next year. The government said the cash would support businesses from January 1, and ensure the province "is ready to seize the trade and investment opportunities ahead". It will be used to promote Northern Irish exports and assist supermarkets and small traders facing new trading arrangements with mainland Britain, the Northern Ireland Office said. Britain left the EU in January but remains bound by the bloc's rules until December 31 as they thrash out new trading terms with Brussels. British prime minister Boris Johnson and European Commission President Ursula von der Leyen have committed to a last-ditch Sunday deadline to decide whether to keep talking. But regardless of the outcome, Britain will leave the EU single market and customs union, and special arrangements will affect goods transiting between mainland Britain and Northern Ireland. An open border with EU member state Ireland was a key plank of the 1998 Good Friday Agreement that brought an end to three decades of violence over British rule in Northern Ireland. To prevent the return of a hard border, Northern Ireland will remain aligned to the EU in key areas, and customs and regulations checks will be required at ports. A deal has been reached to ease the flow of goods between the province and mainland Britain and prevent Northern Irish businesses having to pay tariffs. The EU will also oversee checks at ports. But businesses in the province are still concerned that customs and regulations checks will increase administrative costs. Officials have also warned a lack of port infrastructure may see logjams on lorries arriving in the province. jts/phz/pma