Maryland has secured 500,000 coronavirus tests from South Korea, Gov. Larry Hogan announced on Monday afternoon.

Hogan described the secret Operation Enduring Friendship as unprecedented.

The swab tests — from two South Korean companies — arrived on a chartered Korean Air jet on Saturday, Hogan said. The flight was the first from South Korea to land at Thurgood Marshall Baltimore-Washington International Airport, he said.

The operation required many days and nights of coordination between not only Maryland and South Korean officials but also several federal agencies, Hogan said. There were many other challenges, he said, including the language barrier and a 13-hour time difference.

First lady Yumi Hogan

The governor thanked his wife, whom he said was instrumental in pulling off the operation. She is the nation’s first Korean-American first lady and Maryland’s first Asian-American first lady, her husband said. She joined her husband at the news conference, which was held on the steps of the State House in Annapolis as South Korea’s and Maryland’s flags billowed behind them.

The governor said the locations where the tests would be administered have yet to be determined.