WASHINGTON (AFP) - US President Barack Obama called Egyptian President Mohammed Morsi for the third time in 24 hours on Tuesday and "commended" his efforts to secure a truce in Gaza, the White House said.

"He commended President Morsi's efforts to pursue a de-escalation" in the Gaza Strip, deputy national security advisor Ben Rhodes told reporters traveling home from Asia with Mr Obama during a stopover in Japan.

"He also underscored that President Morsi's efforts reinforce the important role that President Morsi and Egypt play on behalf of regional security and the pursuit of broader peace between the Palestinians and Israelis." The White House said it was the third time Mr Obama and Dr Morsi had spoken in the past 24 hours. "It indicates that Egypt plays a very important role in this process," Mr Rhodes said, adding no additional calls were planned at the moment.

Mr Obama has dispatched US Secretary of State Hillary Clinton to Israel, Egypt and Ramallah, stepping up US efforts to avoid a worsening of the Gaza crisis.

Militants in the Gaza Strip said a truce brokered by Cairo would be announced later Tuesday, and Dr Morsi also said the Israeli "aggression" would end within hours, although the bloodshed showed no signs of abating.

Mr Obama will remain in close touch with Israeli Prime Minister Benjamin Netanyahu, Rhodes said, without offering further information about Mrs Clinton's schedule in the region.

The death toll in the nearly week-long Gaza conflict rose to more than 120 on Tuesday when another 20 people were killed, including a 15-year-old boy who was hunting birds, medics said.

Three Israelis have been killed in rocket fire from Gaza.

Mr Rhodes reiterated that for Washington, any resolution of the conflict must include the cessation of rocket fire into southern Israel.

"Without an end to rocket fire into Israel from Gaza, Israel can't be assured of the security of its people," he said.