After talks with his German counterpart Heiko Maas in Berlin, Hunt told reporters that complacency could lead to Britain crashing out of the European Union without a roadmap for future ties.
“When it comes to Brexit there is now a very real risk of a Brexit no-deal by accident,” he said.
“This is because I think that many people in the EU are thinking that they just have to wait long enough and Britain will blink and that's not going to happen.”
Hunt, who took over from Boris Johnson after his resignation this month, said that “without a real change in approach from the EU negotiators,” both sides could be left struggling to maintain trade and security ties.
“That would be incredibly challenging economically. Britain would find that challenging but in the end we would find a way not just to survive but to thrive economically,” he said.
“But my real concern is that it would change British public attitudes to Europe for a generation and it would lead to a fissure in relations which would be highly damaging for that great partnership that we've had for so many years, that has been so important in sustaining the international order.”
Maas insisted Germany too had an interest in maintaining the closest ties possible with Britain post-Brexit, while stressing that only the European Commission had the power to negotiate the terms.
“We, the German government, don't want a disorderly Brexit, we want a deal,” he said.
“We know that everyone is going to have to take steps toward the other to reach an agreement.
“I hope that the British government and the Commission in Brussels can succeed in sealing a deal that can win a majority in the House of Commons in London but also in the European Parliament in Brussels.”
Maas said Britain and Germany would work together on a bilateral “strategic paper” on foreign policy for the post-Brexit period to ensure as much continuity as possible.
Britain is set to leave the European Union on March 30th next year.
The two sides want to strike an initial withdrawal agreement by late October, in order to give parliament enough time to endorse it, before reaching a broader deal on their future relationship.
However, negotiations have stalled over a range of thorny issues and the Commission, the EU's executive arm, has warned remaining member states and businesses to “step up preparations” for no deal.