Israel decided Wednesday to free 20 Palestinian women from Israeli prisons in exchange for a videotape proving that a captive Israeli soldier held in the Gaza Strip is still alive.

The decision was the first tangible sign of movement in talks that have dragged on for more than three years over the release of the soldier, Sgt. Gilad Schalit.

In a statement, Prime Minister Benjamin Netanyahu's office said Wednesday that it expects Schalit's Hamas captors to release a recent videotape of the soldier. The deal is to be carried out on Friday.

The statement said Israel's Security Cabinet accepted the deal, put forward by Egyptian and German mediators, as a "confidence-building measure." It quoted a senior official in Netanyahu's office as saying the negotiations are still "expected to be long and difficult."

The deal was carried out, the statement said, "ahead of the critical stages in the negotiations for the release of Gilad Schalit and based on Israel's commitment to work with determination to bring him home quickly."

Hamas is demanding that Israel release hundreds of prisoners, many of whom are serving lengthy sentences for violent attacks on Israelis, in exchange for the soldier. Israel has balked at some of Hamas' demands.

In Gaza, Abu Obeida, spokesman for Hamas' militant wing, confirmed that 20 female prisoners were expected to be returned in the coming days. He made no mention of a videotape of Schalit, saying only that Hamas would respond by "clarifying his fate."

A senior Egyptian official involved in the mediation said the move was designed to create "an atmosphere of trust."

"There is no doubt that this step will support the efforts of all sides to solve the problem," he said, speaking on condition of anonymity under security guidelines.

Egypt has been trying to mediate a prisoner swap since Hamas-linked militants tunneled into Israel in June 2006 and attacked an Israeli tank, killing two crewmen and capturing Schalit.

The Israeli soldier has not been seen since his capture and the Red Cross has not been allowed to visit him. But several letters and an audio recording have been released by his captors.

The statement from Netanyahu's office said it was important that the world know Schalit is alive and well and that his safety is Hamas' responsibility.