As optimism grows that a ceasefire deal in the Gaza Strip can be reached, US President Joe Biden and his Egyptian counterpart, Abdel Fattah el-Sisi, say they are committed to remaining in close coordination over the coming hours.

The two leaders have stressed that a ceasefire is urgently needed to allow the release of hostages and to boost humanitarian aid to the conflict-hit region.

The US White House said Biden and Sisi discussed a deal between Israel and the Islamic group Hamas on a ceasefire and the release of hostages by phone on Tuesday.

Separately on the same day, US Secretary of State Antony Blinken said chances for reaching a ceasefire agreement is closer than ever before. He added that they are now waiting for 'final word' from Hamas on its acceptance.

Also on Tuesday, White House National Security Communications Advisor John Kirby said they are still working through some of the gaps that still remain, "but we do believe they are closing."

In the first phase of the three-phase ceasefire plan, Hamas would release more than 30 hostages in about six weeks.

A foreign ministry spokesperson of Qatar, which is also serving as a mediator, noted that negotiations over the final details are under way.