The defense of remote islands, including the creation of an amphibious force, is a high priority in a record-high ¥5.05 trillion budget the Defense Ministry plans to request for fiscal 2015 from next April, government officials said.

Including U.S. military realignment costs, the budget request, to be announced next Friday, is 3.5 percent higher than this fiscal year’s and coincides with Prime Minister Shinzo Abe’s divisive security overhaul.

While a senior ministry official said the increase was mainly caused by the purchase of two new government planes for use by the prime minister and the Imperial family, ¥19 billion is being requested to defend Japan’s remote islands, ¥95.9 billion for buying six F-35 stealth fighters set to become the Air Self-Defense Force’s main fighter jet, and ¥378.10 billion for the bulk purchase of 20 P-1 jets to replace Japan’s fleet of aging P-3Cs.

The island defense measures include creating a new amphibious force and acquiring land to move the U.S. military’s MV-22 Osprey fleet from Okinawa to Saga Airport, the officials said Saturday.

Japan’s increased focus on defending remote islands, especially the Japanese-administered, uninhabited Senkaku Islands in the East China Sea, is a response to China’s growing assertiveness in the area. The islands, which Beijing and Taiwan also claim, remain at the center of strained ties between Tokyo and Beijing.

The ministry will also seek ¥5 million in research costs to introduce new vessels similar to the U.S. Navy’s amphibious assault ships for landing on and retaking remote islands, and ¥35.4 billion for using two passenger ferries to transport Ground Self-Defense Force troops, the officials said.

The ministry will also ask for ¥7 billion to develop new patrol helicopters to step up submarine surveillance, the officials said.