WASHINGTON (AP) — The top American general in South Korea said Friday he is fairly certain North Korea has not been spared by the COVID-19 outbreak that began in neighboring China, although the North has not publicly confirmed a single case.

Speaking by video-teleconference from his headquarters in South Korea, Army Gen. Robert Abrams told reporters at the Pentagon that the North had halted military training for a month — including a 24-day hiatus in military flying — but has since resumed.

“It is a closed-off nation, so we can’t say emphatically that they have cases, but we’re fairly certain they do," he said. “What I do know is that their armed forces had been fundamentally in a lockdown for about 30 days and only recently have they started routine training again. As one example, they didn't fly an airplane for 24 days.” He said they have resumed flying.

Earlier this week, North Korean state media reported that North Korean leader Kim Jong Un supervised his second live-fire artillery exercise in a week. The report Tuesday by Pyongyang’s Korean Central News Agency came a day after South Korea’s military detected the launches of three short-range projectiles off the North’s eastern coast.

Abrams said that only one U.S. service member, among the approximately 28,000 in South Korea, has tested positive for the novel coronavirus. He said efforts to shield the force, including family members and South Korea support personnel, have been largely successful thus far.

The measures Abrams said he has taken to minimize the COVID-19 spread within his force include requiring troops and employees to limit their movement off base, stay home if not feeling well and conducting strict and expansive tracing to identify people who were exposed to anyone who tested positive and require their quarantine.