The Chancellor said “the numbers are definitely worse than what I faced in the spring” as he deals with billions of pounds of higher debt interest payments and a sluggish economy.
Mr Hunt insisted the long-term outlook is strong as long as “difficult decisions” are taken now.
Speaking in Marrakech, Morocco, as he met international finance ministers, he said: “The international situation calls for prudence in the way we manage our finances,” he said.
“The financial picture I face is worse than in the spring and that means I will have to take different positions to make sure, in the face of what’s happening in Ukraine, Israel and parts of Africa, that we are resilient.”
Mr Hunt, who was attending the International Monetary Fund and World Bank annual meetings, said it was a “very challenging environment” in the short term.
Government debt interest “is likely to be £20 billion to £30 billion higher this year than we predicted in the spring”, he added.
The Chancellor, who will give his autumn statement next month, said the economy has proved to be “much more resilient” than nearly every international organisation predicted.
But he said inflation is still too high and international instability means “there is still a lot of shocks”.
“So I need, as Chancellor, to focus on reliance in the face of those shocks,” he added.
“I am very much hoping for the best, but I do need to prepare for the worst, because I think we can see that the world is a very dangerous place right now.
“The numbers are definitely worse than what I faced in the spring.
“Our debt interest is likely to be £20 billion to £30 billion higher this year than we predicted in the spring. So yes, it’s a very challenging environment in the short term.
“But my approach to this is to say we will manage those short-term pressures whilst at the same time building for the long term, doing the things that mean that we can be confident we will be a successful and prosperous economy going forward.
“And as I look at the exciting things that are happening in the longer term in the British economy, I have a great deal of confidence providing we take the difficult decisions necessary to get inflation down, to get our borrowing back under control. If we do these kinds of things then we can be very confident of our future.”
Bank of England governor Andrew Bailey said the UK is in a better position than it was a year ago, when the mini-budget caused chaos.
“From an economic point of view, if we look back over the last year I would say I’m probably the one person that can come in here and say things really do look better today than they did on this day last year,” he said.
“I can say that with some confidence.”
Mr Bailey has previously spoken about his experience of last year’s IMF meeting in Washington, which happened shortly after then-prime minister Liz Truss and then-chancellor Kwasi Kwarteng’s mini-budget.
“People were saying, ‘We didn’t think the UK would do this’,” he told the Treasury Select Committee last year.
On Friday, he said there are signs inflation is coming down but there is much left to do.
He said the Bank’s policy will continue to be “restrictive”.
Mr Bailey added: “We have made, I think, particularly in the last few months, solid progress in terms of showing signs that inflation is being tackled.
“But let’s not get carried away because there’s an awful lot still to do.”
