PARIS (AFP) - European Union leaders on Sunday hammered out a plan to confront the financial crisis which will involve hundreds of billions of dollars of new initiatives to head off a feared "meltdown". Four weeks after the collapse of Lehman Brothers unleashed a worldwide share crash, US and European leaders have signalled a growing commitment to take joint action to end the turmoil. After the Group of Seven wealthiest nations proposed an action plan at weekend meetings in Washington, a Paris summit of the 15 nations that use the euro currency agreed a bank rescue plan, President Nicolas Sarkozy of France said. Sarkozy said governments would buy into banks to boost their finances and guarantee inter-bank lending. "This is indeed a joint action that we are undertaking," Sarkozy told a news conference following a summit of the leaders of the 15-nation eurozone single currency bloc. "This plan addresses all aspects of the financial crisis." Unveiling the action plan, Sarkozy said the countries would unveil the details of their national plans on Monday (today), but that all had agreed a specific series of measures designed to restore confidence in the economic system. The new procedures will be in place until December 31, 2009, he said. European governments that agreed on the joint banking rescue plan will reveal concrete cash figures for their measures on Monday (today), Sarkozy said. "The time for decisions on figures is tomorrow," he said. He argued that to do nothing was not an option. "The crisis has over the past days entered into a phase that makes it intolerable to opt for procrastination and a go-it-alone approach," he said. "We have taken the right course for Europe, for our businesses and our citizens," the President of the European Commission Jose Manuel Barroso said, adding that it would "bring to an end the excessive pessimism of the markets. "Coordinated action is essential for a gradual restoration of confidence." The European Union will ask the United States to jointly organise an international summit to reform the global finance system, Sarkozy said. British Prime Minister Gordon Brown said after the Paris meeting "I believe that in the next few days confidence in the banking system will be restored." He told reporters: "The decisions we take over the next few days will affect us for the years ahead." Europe's economic powerhouses all prepared new individual initiatives to underpin the banking system. Britain, which has already committed more than $700b to a bank rescue, was to take controlling stakes Monday (today) in two major banks worst affected by the crisis, media said. Brown refused to discuss the move but Europe appears to have decided to follow Britain's lead in providing funds to prop up individual banks and free up vital short-term loans between institutions to keep markets moving. Britain has set aside 250 billion pounds (315 billion euros) to guarantee loans, in addition to 200 billion pounds in short term loans and 50 billion to buy stakes in major banks. Germany is expected to guarantee inter-bank loans with between 300 and 400 billion euros ($405 to 540b) and to provide banks with fresh capital in exchange for shares, as in the British plan. German Chancellor Angela Merkel said only the state could now restore "the necessary trust" to the public and financial markets. The French government will on Monday propose a state guarantee for banks endangered by the financial crisis, a ruling party deputy said. Meanwhile in Washington, key nations threw their support behind efforts to tackle the financial turmoil. With governments anxiously hoping to calm markets, the Group of 20 countries which account for 85pc of the global economy said they had agreed to use 'all financial and economic tools' to calm the storm. The Washington meetings and others around the world stressed that efforts would be coordinated. The G20 said action would be "closely communicated so that the action of one country does not come at the expense of others or the stability of the system as a whole," said a joint statement. The 20 nations endorsed a five-point plan agreed by the Group of Seven (G7) industrial powers at the weekend meetings in Washington to prevent the 'failure' of key financial institutions. US President George W Bush said the world's richest economies were united on a 'serious global response' to the financial meltdown. International Monetary Fund chief Dominique Strauss-Kahn claimed a breakthrough with the first global pledge to cooperate to stabilise the turmoil. He had earlier warned, however, that the financial system risked collapse. "Intensifying solvency concerns about a number of the largest US-based and European financial institutions have pushed the global financial system to the brink of systemic meltdown," he said.