The European Commission stands ready to aid countries hit by Britain's departure from the European Union and other external shocks, Budget Commissioner Guenther Oettinger said on Friday.

Several billion euros had been earmarked in the next budget cycle, starting 2021, to soften so-called asymmetric shocks in which a part of the EU slides into recession because of external factors, Oettinger said.

"If for example, Ireland, because of the border with Northern Ireland and therefore with Britain is impacted, or if a conflict would emerge in the neighbourhood of Estonia, Latvia or Lithuania and this would lead to an extraordinary deterioration of the economy (...) we have a programme of several billion to stabilise the economy," Oettinger told reporters at a news conference in Sofia.

Several regions, including Ireland and the Flanders region of Belgium which depend heavily on exports to Britain, have in the past warned about the economic price of the country's departure from the EU.

Flanders' exports to Britain are worth some €28 billion per year and the Flemish government said sales to Britain could shrink up to 2.5 per cent in case of a hard Brexit.