tokyo japan prepare acquire precision air-launched missiles first time would give capability strike north korean missile sit two source direct knowledge matter say japan plan put money aside next defense budget start april study whether f-15 fighters could launch longer-range missiles include lockheed martin corp extended-range joint air-to-surface standoff missile jassm-er hit target 1,000 km 620 miles away say one source knowledge plan global trend use long range missiles natural japan would want consider say source ask remain anonymous authorize talk media japan also interest buy 500 km-range joint strike missile design norway kongsberg defence aerospace carry f-35 stealth fighter fuji television report early neither two items include 5.26 trillion yen 46.76 billion budget request already submit japan ministry defence however additional fund would make available evaluate purchase missiles source say change suggest grow threat pose north korean ballistic missiles give proponents strike capability upper hand military plan restrictions strike weapons impose war-renouncing constitution mean japan missile force compose anti-aircraft anti-ship munition range less 300 kms 186 miles decision buy long range weapons capable strike north korea even chinese mainland would therefore controversial proponents argue strike weapons play defensive role currently look fund japanese defense minister itsunori onodera say tuesday regular press brief rely unite state strike enemy base look make change share roles add take post august onodera lead group rule liberal democratic party lawmakers recommend japan acquire strike weapons deter pyongyang launch attack japan north korea since fire ballistic missiles japan last week test new type intercontinental ballistic missile climb altitude 4,000 km splash sea japan within japan exclusive economic zone japan want missiles enough range strike north korea source