It's all smiles are on the surface but tensions are definitely building. Russia is the latest currency war battleground as G20 countries meet in Moscow. Finance ministers are sparring over how to deal with ultra loose monetary policies from Japan and the US. There are fears it could trigger a chain of competitive currency devaluations. Expectations of an agreement are low, says William De Vijlder from BNP Paribas. SOUNDBITE (English) BNP PARIBAS INVESTMENT PARTNERS CIO WILLIAM DE VIJLDER, SAYING: "It'll be a big leap of faith that something will come out of the G20.The issue is that a currency is the ultimate expression of monetary autonomy. So countries will be very reluctant to give in to external pressure to commit to something." The stakes got higher this week after G7 nations issued a joint warning against currency targets. It was supposed to calm tensions but a string of critical off-the record briefings exposed the group's divisions. Japan was the focal point - its policies have seen the yen drop 20% since November. But the Bank of Japan's Governor defended the approach. (SOUNDBITE) (Japanese) BANK OF JAPAN GOVERNOR MASAAKI SHIRAKAWA, SAYING: "I believe each country's policies, aimed at stabilising their own economies, will lead to stability of the global economy on the whole." The euro's got the opposite problem. It's been getting stronger, making exports more expensive, and fuelling fears it could choke a recovery. But ECB President Mario Draghi is so far refusing to step in. (SOUNDBITE) (English) EUROPEAN CENTRAL BANK PRESIDENT MARIO DRAGHI, SAYING: "All this chatter that has been undertaken in the last few weeks about exchange rates is either inappropriate or fruitless. In all cases it is self-defeating." Growth versus austerity is another row that's brewing, this time between Europe and the US. Germany's pressing the US to cut its deficit; Washington wants Berlin to do more to stimulate demand. It's a more familiar battle than currency, but one that's equally unlikely to conclude any time soon.