Israel stopped short of confirming the timing of what it said would be an informal arrangement to halt fighting.

Mark Regev, a spokesman for Ehud Olmert, the Israeli prime minister, said Israel would continue preparations for broad military action should a truce fall apart.

"What is important is not words but actions," he said, repeating Israel's demands for an end to attacks on Israeli civilians, a halt to arms smuggling into the Gaza Strip and progress towards the release of Gilad Shalit, an Israeli soldier seized by Gaza fighters two years ago.