A White House plane carrying first lady Michelle ObamaMichelle LeVaughn Robinson ObamaJill Biden adds to communications team in lead-up to midterm elections Michelle Obama: 'Treat fear as a challenge' Barack Obama wishes a happy 58th birthday to 'best friend' Michelle MORE was forced to abort its landing Monday at Andrews Air Force Base after it came too close to a military cargo plane, the Federal Aviation Administration confirmed Tuesday.

A Boeing 737 carrying the first lady was instructed to circle Andrews because there did not appear to be enough time for a military C17 airplane to clear the runway. The plane carrying Obama had been given clearance to approach for a landing by air traffic controllers.

The FAA said it was investigating the incident, and stressed that no one was harmed, including the first lady.

"The Boeing 737 landed safely after executing the go-around," the agency said in a statement. "The aircraft were never in any danger."

The White House referred requests for comment to the FAA.

The Washington Post first reported the incident Tuesday, citing anonymous federal officials saying that the incident occurred due to an air traffic controller's error.

The FAA is already dealing with a series of controversies regarding air traffic controllers falling asleep or being distracted on the job. Transportation Secretary Ray LaHood said this weekend that his agency is making changes to controller's schedules to prevent future problems.

FAA investigators were sent to the control center where the controller's error was made.

Obama was returning from New York, where she participated in a television interview with second lady Jill Biden.

—This post was updated at 6:10 p.m.