TOKYO -- Japan's Defense Ministry is likely to request a budgetary allocation so the country's air force, which is responding more frequently to Chinese provocations, can load more missiles on its F-15 fighter jets, sources said.

The ministry wants to double the number of air-to-air missiles to be loaded on the mainstay jets, operated by the Air Self-Defense Force. It also plans to lengthen the jets' lifespans.

The ministry would like the money to be allocated in the budget for the fiscal year beginning in April.

There has been a surge in the number of Chinese warplanes as well as increased Chinese provocations in waters around the Senkaku Islands, in the southernmost Japanese prefecture of Okinawa. China also claims the islands, calling them the Diaoyu.

The ministry appears to want to counter China's moves by both souping up existing jets and introducing next-generation fighters.

The ASDF owns 200 F-15s, fourth-generation fighter jets made by Boeing, the U.S. aerospace and defense company.

The ministry plans to double the number of missiles each jet can carry to 16. It also plans to repair damaged wings and other parts to extend operating life.

The ASDF has been scrambling jets more often in response to Chinese maneuvers. It did so 199 times from April through June, a 75% increase from the same period last year.

Recently, Chinese jets have been flying further south, near the contested islands. "As the cruising range of Chinese military aircraft has gotten longer, they are coming ever closer to our territories," a Japanese Defense Ministry official said.

In January, the ASDF transferred its squadron at the Tsuiki air base in Fukuoka Prefecture, southern Japan, to a base in Naha, Okinawa, nearly doubling the number of F-15s there to 40. Were China to send a big squadron into Japanese airspace, Tokyo would need to respond with both quality and quantity.

At the end of fiscal 2017, the ASDF is to deploy fifth-generation F-35 stealth fighters that are hard to detect by radar. But the first F-35s will be deployed at the Misawa base in Aomori Prefecture, at the northern tip of Japan's main island. The U.S. Air Force shares the base, and the ASDF plans to first work on joint pilot training and maintenance cooperation with the U.S. before putting the jets in operation in tenser areas.

(Nikkei)