The call between the defense chiefs came on the same day that hundreds of pagers used by Hezbollah members exploded in an attack the Lebanese militant group blamed on Israel, but the Pentagon declined to say whether the explosions were discussed.

"Secretary Austin spoke by phone today with his Israeli counterpart to touch base regarding ongoing tensions in the Middle East and the threats facing Israel," Pentagon spokesman Major General Pat Ryder told journalists.

Austin "reiterated the need for a ceasefire and hostage deal, and the importance of reducing tensions through diplomacy to prevent the potential for a wider regional conflict," he said.

There was no immediate comment from the Israeli military on the wave of pager explosions, which killed at least nine people and wounded some 2,800.

The blasts came just hours after Israel announced it was broadening the aims of the war sparked by the Hamas attacks to include the safe return of residents of northern Israel who have been displaced by its fight against Hezbollah along its border with Lebanon.