EU leaders are to meet in Brussels without the UK for the first time since Britons voted to leave the EU.
The heads of state of 27 European Union members are meeting for the first time without the UK following last week's referendum in which Britons voted to leave the bloc.
British Prime Minister David Cameron arrived in Brussels on Tuesday to come face to face with EU leaders as part of a summit focusing on how to deal with the UK's decision to leave.
The outcome of the referendum sent shockwaves across the continent, triggering calls for similar referendums in other European countries which could ultimately end the bloc for good.
Following Cameron's subsequent announcement of his plan to step down, the pound sterling currency dropped to its lowest value in 30 years.
The EU has been pressuring the British government to immediately begin what is expected to be a two-year process since 51.9 percent of Britons expressed their wish to pull out.
But Cameron, who is in Brussels trying to lobby support for a good departure deal, is determined to delay negotiations till after he steps down as prime minister in September.
"Everyone wants to see a clear model appear" for Britain's future relations with the bloc, he told his EU counterparts on Tuesday, adding that he "can't put a timeframe on that."
The outgoing premier also told reporters after a dinner meeting with his fellow EU leaders that discussions had been "calm, constructive and purposeful" and there was "universal respect" for the UK's decision despite a "tone of sadness and regret."
"Britain will be leaving the European Union but we will not be turning our back on Europe," he reassured.
EU nations have been particularly concerned about the domino effect the falling pound sterling could have on their own economies.
European Central Bank President Mario Draghi said on Tuesday that central banks around the world should aim to align monetary policies to mitigate "destabilising spillovers" between economies.
Draghi had added that he agreed with private economists who predict eurozone growth will be reduced by up to 0.5 percent cumulatively over the next three years due to the "Brexit" vote.
EU leaders fear the lingering of the current state of uncertainty will only destabilise the bloc even more.
"We are not on Facebook, where things are complicated. We are married or divorced, but not something in between," Luxembourg Prime Minister Xavier Bettel said.
EU Council President Donald Tusk said he was planning a special meeting of the EU leaders in Slovakia in September to chart a way ahead.
EU Commission President Jean-Claude Juncker said he had banned his policy commissioners from holding any secret talks with Britain on its future until London triggers the exit clause.