Amid growing concerns that the debt crisis in Greece could spread to other heavily-indebted nations in the region, Germany and France have called for better internal surveillance to prevent a recurrence of a similar crisis. Chancellor Angela Merkel and French President Nicolas Sarkozy said in a joint letter to the European Commission president that just dealing with the Greek debt crisis alone will not be enough to preserve the success story of Europe's economic and monetary union. The letter comes on the eve of an emergency summit of euro group heads of state and government in Brussels today. The two leaders said that they need to go further in drawing up lessons from the crisis and in taking all necessary measure to make sure that such a crisis will not happen again. The summit has been convened to formally endorse the three-year 110 billion-euro financial aid package to rescue Greece from bankruptcy, which was agreed by the finance ministers of the euro zone nations and the International Monetary Fund last Sunday.