* Euro rises 1 pct against dollar, yen * ECB head says will do whatever needed to save euro * Analysts say gains may be short-lived NEW YORK, July 26 (Reuters) - The euro soared against the dollar and other major currencies on Thursday, reversing earlier losses, after European Central Bank chief Mario Draghi said the bank would do whatever it takes to preserve the single currency. The euro touched a fresh one-week high against the dollar after the number of Americans filing new claims for jobless benefits fell last week to near a four-year low, a hopeful sign for a labor market that has shown signs of weakness and prompting investors to increase risk exposure. The euro rose 1 percent to a one-week high of $1.2315, using Reuters data, well above a session low of $1.2116 touched earlier in the global trading day before Draghi's comments. Speaking at a conference in London, Draghi pledged to do whatever was necessary to protect the euro zone from collapse, including fighting unreasonably high government borrowing costs for countries such as Spain and Italy. But analysts were skeptical the euro's gains would be sustained given worries about the possibility of Spain applying for a sovereign bailout or Greece leaving the monetary union. "In a heavily biased market, it only takes a little bit of news of the opposite sentiment to provoke quick moves," said Christopher Vecchio, currency analyst at DailyFX. "Such has been the case in the Euro today, which has rapidly appreciated to its weekly high against the US Dollar following constructive commentary from European Central Bank President Mario Draghi today." Better investor appetite to take on risk dented the safe-haven U.S. dollar, which lost more than 1 percent against the Swiss franc and New Zealand dollars and almost as much against the higher-yielding Australian. The euro also gained more than 1 percent against the Japanese yen to 96.20 yen. But analysts said there was little new or of substance in recent comments by policymakers and they expected traders to eventually sell into any rally. They said the past two days' gains may have been overdone and the euro could re-test recent lows and target the psychological $1.20 level followed by 2010's low around $1.1875. "The only thing that could change the downtrend in the euro is if the Fed launched further quantitative easing or some other additional policy measures. Otherwise it's all about what happens in the euro zone," said Richard Falkenhall, currency strategist at SEB in Stockholm. Any hints at further quantitative easing at a U.S. Federal Reserve policy meeting next week could bolster the euro, as asset buying by the central bank would increase the supply of dollars in the market and weigh on the greenback. Speculation the Fed may adopt monetary easing steps could grow louder if U.S. second-quarter gross domestic product data due on Friday is weak, although most expect the central bank to hold back for now. New orders for a range of long-lasting U.S. manufactured goods fell in June and a gauge of planned business spending plans dropped, pointing to a slowdown in factory activity, a report showed on Thursday. "The slow accumulation of negative data will eventually force the Fed to act," said Joseph Trevisani, chief market strategist at Worldwide Markets, Woodcliff Lake in New Jersey. "Today's mixed durable goods orders, with the headline result better than expected and the ex-transportation worse, does not change the economic slide toward recession."