Japan is to consider using unmanned aircraft for surveillance flights, a newspaper reported Thursday, at a time of heightened tensions with neighbouring China and North Korea.

Japan will send military officials to the United States, which uses the cutting-edge Global Hawk high-altitude surveillance aircraft, to study how they operate and maintain the drones, the Yomiuri daily said.

The defense ministry will start fully fledged research in the next fiscal year starting April, and intends to make a final decision on whether to deploy such aircraft by the end of fiscal 2015, according to the report.

The drones can fly at an altitude of 18,000 metres (almost 60,000 feet) and have a surveillance radius of 550 kilometres in any direction, the daily said. Three of them would cover Japan and surrounding maritime territories, it said.

The report did not say where Japan might deploy the drones or say whether they would be used to overfly foreign territories.

The drones, excluding sensors, cost about 2.5 billion yen (30 million dollars) each, according to the report.

With ground facilities, initial costs are estimated to total tens of billions of yen, the Yomiuri quoted defense ministry officials saying.

Japan, in a major strategic review adopted on December 17, mentioned the possibility of deploying unmanned aircraft.

The review came in a year when Japan and China have argued bitterly over long-disputed maritime territories, and when nuclear-armed North Korea heightened regional tensions with a deadly artillery strike against the South.