The Washington Monument will be closed indefinitely as work to repair the elevator continues, officials announced Monday morning.

"Despite the continuing work on the Washington Monument elevator, we have not been able to determine the causes of the ongoing reliability issues," the National Park Service (NPS) said in a statement. "As a result, we have made the difficult decision not to reopen the Washington Monument until we can modernize the elevator control system."

The elevator was repeatedly broken, trapping passengers and forcing visitors to the monument to walk down dozens of flights of stairs.

NPS will give an update in "the next couple weeks" on how long the repairs will take.