* Yen sharply higher vs Australian and New Zealand dollars * Swiss franc rises versus euro, dollar * Emerging market currencies in rout on Syria tension * German IFO survey has little impact on euro/dollar By Julie Haviv NEW YORK, Aug 27 (Reuters) - The safe-haven yen and Swiss franc rose on Tuesday and riskier currencies including the Australian and New Zealand dollars fell, as investors became jittery with Western countries poised to take military action against the Syrian government. Western powers told the Syrian opposition to expect a strike against President Bashar al-Assad's forces within days, according to sources who attended a meeting between envoys and the Syrian National Coalition in Istanbul. That news trumped economic reports that would have typically fostered risk taking, such as an upbeat German business sentiment survey. "It seems that today is a good old risk-off day due to Syria," said Charles St-Arnaud, foreign exchange strategist at Nomura Securities in New York. "This explains why the yen has been outperforming the dollar and why the dollar has been outperforming most other currencies, especially the Australian dollar, New Zealand dollar and emerging market currencies," he said. The dollar last traded down 1.5 percent against the yen, at 97.04 yen, not far from a one-week low of 96.97 yen reached earlier and well off a near three-week high of 99.15 yen set on Friday. The euro also struggled against the yen, falling 1.3 percent to 129.94 yen. Against the Swiss franc, the dollar fell 0.6 percent, to 0.9178 franc, while the euro was down 0.5 percent at 1.2286 francs. "Investors are unwinding carry trades as the growing risk of an international response to Syria drove all of the major currencies lower against the U.S. dollar and Japanese yen," said Kathy Lien, managing director at BK Asset Management in New York. The Swiss franc and the yen usually climb in times of financial market stress and geopolitical uncertainty, while growth-linked higher-yielding currencies sell off. In the case of the dollar, the greenback was bought against emerging market currencies. German, U.S. and British government bond prices all rose as money flowed into safe-haven markets. Stocks were sharply lower. The growth-linked Australian dollar was down 0.4 percent at US$0.8994, while against the yen it lost 1.8 percent, to 87.28 yen. The New Zealand dollar fell 2.1 percent against the yen, to 75.74 yen. Washington said on Monday it believed the Syrian president was responsible for a chemical weapons attack on civilians last week in what U.S. Secretary of State John Kerry called a "moral obscenity." Emerging market currencies tumbled, with the Indian rupee hitting a record low and the Russian rouble, the Indonesian rupiah and a host of others recording multi-year troughs. The rising tension stemming from Syria overshadowed the impact from positive data from the euro zone and United States. The IFO German confidence survey showed business sentiment was at its highest level in 16 months, but that had only a fleeting impact on the euro. In the United States, consumer confidence improved this month, while home prices rose in June on a seasonally adjusted basis, according to the S&P/Case Shiller composite index of 20 metropolitan areas. The euro was last up 0.2 percent against the dollar at $1.3392. Disappointing U.S. data in the past two trading sessions, including a report that highlighted the fragility of the housing sector, have weighed on the dollar, although buying at lower levels has checked sharp losses. The dollar index, which tracks the greenback against a basket of six major currencies, was last down 0.3 percent at 81.138, according to Reuters data.