A jet comes in for landing at Los Angeles International Airport (LAX) on April 15, 2008 in Los Angeles, California. David McNew/Getty Images

The Federal Aviation Administration (FAA) on Monday confirmed that system-wide computer issues had caused massive delays for six U.S. airlines, leading to long wait times and missed connections.

The problem stemmed from a software glitch from a vendor's airplane planning weight and balance program, but the issue had been resolved, according to a statement by the FAA.

The vendor, Scottsdale, Ariz.-based AeroData Inc., provides software that calculates the weight and balance of flights before takeoff.

Nearly 2,000 flights within, into, or out of the U.S. were delayed on Southwest, Delta, United, JetBlue, American and Alaska.

Tracking service FlightAware reported that Southwest suffered 620 delays.

"Southwest Airlines has issued a ground stop this morning as a result of a technology outage involving a vendor that provides aircraft weight and balance data," Southwest said in a statement.

United Airlines said about 150 flights were impacted.