Tokyo, Feb 20: Japan said it has signed a USD 2 billion deal with Iran to develop the massive Azadegan oilfield in order to assure stable oil supplies despite the US expressing "deep concern" over the deal. A Japanese trade ministry official said the two sides signed an agreement early on Thursday on the development of the Azadegan field in south-western Iran after months of negotiations and repeated warnings from Washington that it was unhappy with the prospects of such an accord. Ever since the 1973 oil crisis, Japan, which imports nearly all of its oil needs, has developed its diplomacy with oil producers in West Asia, often putting it at odds with the US, especially over Iran, dubbed part of an "axis of evil" by president George W Bush. The Japanese government said it hoped the deal would lead to stable energy supplies. Bureau Report