Secretary of State Antony Blinken will land in Tel Aviv, Israel, on Sunday evening as talks over a Gaza cease-fire hang in the balance.

Following discussions in Doha, Qatar, this week, senior officials are due to meet again next week in Egypt. Israel has said it will send a team to Cairo to continue talks, but Hamas has dismissed any hint of progress as an illusion.

Vedant Patel, the State Department’s principal deputy spokesperson, told reporters at a Thursday briefing that the parties are yet to settle "some specific details, some specific implementing factors," but that there is "broad agreement on the contours" of a proposal set out by President Joe Biden in May.

Israeli Prime Minister Benjamin Netanyahu has expressed "cautious optimism" of progress, though one Israeli official said that "gaps" remain on sensitive topics, including whether or not Israeli forces will withdraw from key strategic areas within Gaza.

Meanwhile, the death toll continues to grow in the devastated strip. This weekend, more than 60 people were killed in Israeli airstrikes, according to the Hamas-controlled Health Ministry.

-ABC News’ Joe Simonetti and Tom Soufi Burridge

With a cease-fire deal "now in sight," President Joe Biden said in a statement Friday that "no one in the region should take actions to undermine this process."

Biden said his teams will "report to me regularly" as they remain on the ground over the coming days. Senior officials "will convene again in Cairo before the end of the week," he said.

The expectation is for a cease-fire to go into place soon after there is agreement between the parties, a source familiar with the talks told ABC News.

-ABC News' Justin Gomez

A 10-month-old baby has become the first confirmed case of polio in Gaza, as international aid organizations and the United Nations push for a temporary humanitarian cease-fire to administer polio vaccinations, according to the Palestinian Ministry of Health.

The baby, located in is in Deir al-Balah, had not received a polio vaccination.

"The continued brutal Israeli aggression on the Gaza Strip has resulted in a health disaster, as attested by international organizations. The lack of basic hygiene needs, the lack of sanitation services, the accumulation of waste in the streets and around the places where displaced persons are sheltered, and the lack of safe drinking water have created an environment conducive to the spread and transmission of many epidemics, including waterborne diseases such as the vaccine-derived polio virus," the ministry said in a statement.

U.S. Secretary of State Antony Blinken will travel to Israel on Saturday amid reports Hamas and Israel are close to a cease-fire deal.

Blinken will head to Israel Saturday to "continue intensive diplomatic efforts to conclude the agreement for a ceasefire and release of hostages and detainees through the bridging proposal presented today by the United States, with support from Egypt and Qatar," according to the state department.