South Korea has taken delivery of the first of four RQ-4 Global Hawk surveillance drones, according to local media reports.

The unmanned aircraft landed early Monday at Sacheon Air Base in South Gyeongsang province, South Korean broadcaster KBS reported.

The U.S. Department of Defense announced its approval of the high-tech aircraft’s sale to South Korea in December 2017. The $657 million deal included the drones, spare engines and ground-control equipment.

South Korea’s military plans to deploy three more Global Hawks by the first half of 2020, the KBS report said.

The Northrop Grumman-built drones are thought to be capable of operating at an altitude of 60,000 feet, high above civilian air traffic, which normally does not surpass 40,000 feet. They can stay aloft for 34 hours and have a range of 14,000 miles.

Defense experts have said that U.S. Air Force Global Hawks flying out of Andersen Air Force Base on Guam and Misawa and Yokota air bases in Japan during summers could be useful tools for keeping tabs on North Korea’s nuclear program.

North Korea has set a year-end deadline for Washington to offer concessions to restart stalled nuclear talks.

Early this month, the North announced it had successfully conducted a “very important test” at a long-range rocket launch site, spurring President Donald Trump to warn that North Korean leader Kim Jong Un could lose “everything” if he acts aggressively.

A day after the test, a North Korean diplomat prompted speculation that Pyongyang might be preparing for a long-range missile test, saying it was “entirely” up to the United States what “Christmas gift” it wants as the year draws to a close.

Stars and Stripes reporter Yoo Kyong Chang contributed to this report.

robson.seth@stripes.com

Twitter: @SethRobson1