European Council President Charles Michel has said that EU talks with Britain on their new relationship were "not easy" and countries, regions and industries will face disruptions from 2021 whether there is a new pact or not.

Laying out his compromise proposal for a multi-billion-euro economic stimulus for the EU to recover from the coronavirus pandemic, Michel said a new Brexit "adjustment reserve" of 5 billion euros ($5.64 billion) was also needed to "counter the unforeseen consequences" of Britain's departure.

Michel said the EU’s executive European Commission should review by February 2021 the first consequences of the new reality between Britain and the bloc, and the money could then be used to support those most affected in Europe.

"Hope for the best, prepare for the worst: a sound principle in politics," Belgian Prime Minister Sophie Wilmes said in reaction to the proposal that will be debated by the 27 national EU leaders in Brussels next week.

Britain left the EU in January but is still covered by a status-quo transition phase until the end of the year to allow time to negotiate new ties from trade to security.

Negotiations have so far stalled over differences on fisheries and fair competition guarantees, among others. British Prime Minister Boris Johnson only wants a loser trade pact with the EU from 2021, while the bloc seeks much closer links in many other areas, including security.

Talks this week in London between EU and British negotiators, briefly joined by Johnson at a No.10 dinner, brought no breakthrough and more negotiations are due next week in Brussels.

"There are significant differences that still remain on a number of important issues," a spokesman for Johnson said on Friday.