Chancellor Alistair Darling has hailed the G20 summit as an "essential part" of fixing the global economy but warned there were no overnight solutions.
He said the agreements reached by world leaders were a "very significant step forward", adding: "You cannot oversell what happened yesterday, nor can you undersell it."
Mr Darling pledged that the global economy "will get through this" when asked about the extent of the crisis.
He added: "When people ask me, as they will, 'OK, you reached this agreement in London yesterday - what does it mean for me?', my answer is this is part of a process that will help us ensure that we can protect jobs, there will be jobs there in the future as we get into recovery, that we can get credit flowing again."
Prime Minister Gordon Brown hailed the creation of a "new world order" after two days of intense negotiations with international leaders agreed a series of measures to tackle the global economic downturn.
The key plank of the deal is an injection of 1.1 trillion dollars of additional resources for the International Monetary Fund (IMF) and other international institutions.
The IMF's resources will be trebled from 250 billion dollars to 750 billion dollars, while the special drawing rights made available by the IMF - which can be converted by national governments into currency for a swift injection of liquidity into their economies - will be increased by a further 250 billion.
There will a 250 billion dollar trade support package through the World Bank, while lending to low-income countries by the multilateral development banks - including the World Bank - will be increased by at least 100 billion dollars.
New rules on bankers' pay will mean no more rewards for failure, and the international regulatory system will be extended to cover some hedge funds and other elements of the so-called "shadow banking" system.
A new financial stability board will be established to work with the IMF to provide early warnings of emerging problems in the financial system, and tax havens which refuse to accept international rules will face sanctions.
