Nikkei jumps as yen breaches 100 to dollar mark Japanese officials have repeatedly said the stimulus measures are only aimed at strengthening the nation's stagnant economy. "We are not touching on the currency market but rather trying to exit from deflation," Finance Minister Taro Aso told reporters on Friday before boarding a plane to attend a G7 meeting in Britain. However, some observers have warned that Tokyo's policy of big spending and aggressive central bank monetary easing could backfire, inflating Japan's national debt which is already the worst in the industrialised world at more than twice the size of the economy. "The cheaper yen certainly has a positive impact on Japanese companies but for the Japanese economy to take off it may not be enough," said Hisao Matsuura, strategist at Nomura Securities. A weakening currency makes imports more expensive, affecting petrol and food prices, which would weigh on domestic demand while Japanese firms must also account for higher costs of materials purchased overseas and rising energy costs, Mr Matsuura said. Masamichi Adachi, senior economist at JPMorgan, said the dollar above 100 yen was "what everyone had expected and there is no surprise in it." "But in terms of its impact on the Japanese economy, it's definitely positive in the short-term," he said. Prime Minister Shinzo Abe has faced pressure from the Organization for Economic Cooperation and Development and the Group of 20 leading economies to present a plan to confront Japan's staggering public debt, which would involve austerity measures that run counter to current policies. Japan has also been the target of veiled warnings from the United States and Europe, as well as emerging economies, over the yen's sharp fall. Last month, Washington warned Tokyo "to refrain from competitive devaluation and targeting its exchange rate for competitive purposes." The International Monetary Fund and the G20 have both given approval to the BoJ effort, but they too have cautioned over the currency war risk. The dollar's rise past the 100-yen line Thursday was also driven by improved US economic data, including unexpectedly strong jobs market numbers. A US Department of Labor report on Thursday showed fewer unemployment benefits claims than expected, which gave the dollar a boost, analysts said.