British Prime Minister David Cameron is to meet European Union leaders on Tuesday for the first time since the UK voted to leave.
The UK prime minister will discuss the implications of the Brexit vote and the way ahead at an EU summit in Brussels.
Also in Brussels, MEPs are holding an emergency session to debate their response to the UK's referendum.
Meanwhile, Health Secretary Jeremy Hunt has suggested a second referendum - or a general election - to be held over the terms of the UK's departure.
Mr Hunt said the withdrawal process should be delayed until shortly before the next election - meaning a delay until after 2022 at the earliest.
He is the first cabinet minister to go public with the idea of a second referendum.