Four completed helipads for the U.S. military are seen in the subtropical jungle of Kunigami, a village in Okinawa Prefecture. (Mitsuru Matsui)

HIGASHI, Okinawa Prefecture--Four U.S. military helipads in the subtropical forest near a community in this village have been completed despite high-profile demonstrations staged for months by protesters to hamper construction.

Officials with the Defense Ministry’s Okinawa Defense Bureau and personnel with the U.S. military confirmed the completion of the helipads by Dec. 16, ministry sources said.

The helipads were built in the Northern Training Area, also known as Camp Gonsalves, which straddles Higashi and neighboring Kunigami village in northern Okinawa Prefecture. They will be used by MV-22 Osprey aircraft deployed to U.S. Marine Corps Air Station Funtema to the south in Ginowan in the prefecture.

In a 1996 bilateral pact, the United States agreed to return 4,000 hectares of Camp Gonsalves to Japan, more than half of the land in the jungle training area, on the condition that six helipads would be constructed in the portion retained by U.S. forces.

The Japanese government's construction of the four facilities started in July, sparking fierce opposition by anti-U.S. base protesters in the prefecture and elsewhere over concerns including noise, safety and the environmental impact. The locations are close to the Takae community of Higashi.

Two helipads were completed in 2014, also near Takae.

A report by the U.S. military compiled in 2012 showed that the Osprey will use each of the helipads 420 times a year.