Christine Lagarde says the IMF hopes Brexit will "be conducted promptly to reduce the level of uncertainty"
The head of the International Monetary Fund (IMF) has said she "cannot imagine" there will be no deal on Brexit.
At the IMF's annual meeting in Washington, Christine Lagarde made her most strongly worded intervention since the negotiations began, urging both sides to seek a deal for the sake of their people.
Asked about the chance of there being no deal between Britain and Europe, she said: "I just cannot imagine that that will happen."
She raised the prospect of EU citizens being trapped in the UK and vice versa, saying that the World Trade Organisation arrangements the UK would potentially fall back on if it left without a deal "does not provide for such eventualities".
"I think of the airline industries, the landing rights in various European countries," she said.
"There is so much that has been brought together between the continent and the UK that it requires a very specific approach that will reduce the uncertainty that is damaging potential."
Ms Lagarde's comments underline the degree to which international authorities have yet to take seriously the prospect of Britain leaving the EU without securing a transitional deal, or a long-term arrangement.
They come amid consternation from both sides about the slow progress of the talks, which are still bogged down in negotiations about the size of the UK's divorce bill.
Ms Lagarde said: "Our hope is that [Brexit] be conducted promptly to reduce the level of uncertainty and the anxiety of people about the outcome and the situation of people first, of business second. Because this is affecting the people and the businesses.
"I don't know if the two-year transition is going to be agreed upon as it was proposed by Prime Minister May but certainly, clarity on the timetable and better certainty on the three pillars which are the beginning of the negotiations would help reduce this uncertainty."