Japan plans to spend $2.1 billion on its military over the next few months as part of a huge stimulus package, a defence ministry official said, amid growing concerns over a rising China. The cash is in addition to the regular military spending for 2012-13 and is separate from a boosted budget request for next fiscal year that ruling party policy makers called for on Tuesday. \"We will request 180.5 billion yen to be allocated to military spending from a stimulus package,\" a defence ministry spokesman told AFP, adding that some of the cash will be used to buy PAC-3 surface-to-air anti-ballistic missile systems and modernise four F-15 fighter jets. The request for funds has to be approved by the finance ministry before being officially included in the stimulus the government is set to announce later this month, reportedly worth 13.1 trillion yen for this fiscal year to March. The announcement came a day after Prime Minister Shinzo Abe\'s ruling Liberal Democratic Party said Japan will increase military spending for the first time in 11 years next fiscal year starting from April. Japan is involved in a territorial tussle with China over a group of uninhabited islands in the East China Sea. Beijing has sent vessels to the area dozens of times and late last year dispatched a plane. Nerves in Tokyo have also been rattled by an unpredictable North Korea. It sent a rocket over Japan\'s southern islands last month in what it insisted was a satellite launch. Tokyo and its allies said the launch was a covert ballistic missile test. \"Out of 180.5 billion yen, the defence ministry plans to use 60.5 billion yen to prepare for the changing security environment surrounding Japan,\" the spokesman said. The defence ministry also plans to purchase three SH-60K patrol helicopters and to add a battery for an intermediate-range ballistic missile system, he said. \"We need to update our equipment as the security environment surrounding Japan is becoming harsher as North Korea has test-launched missiles twice in the last year and tensions with China continue,\" he said. Under usual precedent, 70-80 percent of a defence order must be spent with domestic firms, although this is not a legal requirement, he said.