The Holloway case has followed many twists and turns.
Two years ago, a Dutch television crime reporter captured hidden-camera footage of van der Sloot saying he was with Holloway when she collapsed on a beach from being drunk. He said he believed she was dead and asked a friend to dump her body in the sea. Judges subsequently refused to arrest van der Sloot on the basis of the tape.
Aruba's attorney general, Taco Stein, said Thursday that the island would offer assistance to investigators in Peru when van der Sloot arrives there.
He said van der Sloot remains the only suspect in the Holloway case. "There is always hope," he said.
Associated Press writers Eva Vergara in Santiago, Chile, Carla Salazar in Lima, Mike Warren in Buenos Aires and Michael Melia in San Juan, Puerto Rico, contributed to this report.