Biden's comments, recorded on Monday and broadcast after midnight on Tuesday, come as negotiators try to hammer out the first extended truce deal in a war that has obliterated the Gaza Strip since October last year.
"Ramadan is coming up, and there’s been an agreement by the Israelis that they would not engage in activities during Ramadan, as well, in order to give us time to get all the hostages out," Biden said on NBC's "Late Night with Seth Meyers".
Earlier on Monday, Biden said he hoped a ceasefire agreement would be hammered out by Monday, March 4. Ramadan is expected to begin on March 10.
"My national security adviser tells me that they’re close. They’re close. They’re not done yet. My hope is by next Monday we’ll have a ceasefire," Biden said.
Hamas is reviewing a proposal agreed at a meeting in Paris last week between Israel, the United States and mediators from Egypt and Qatar, the most serious push for a ceasefire since the last truce collapsed after a week in November.
Two senior Hamas officials said Biden's remarks suggesting the agreement had already been reached in principle were premature.
There were "still big gaps to be bridged", one Hamas official told Reuters. "The primary and main issues of the ceasefire and the withdrawal of Israeli forces are not clearly stated, which delays reaching an agreement."
A senior source close to the talks told Reuters that the draft proposal sent to Hamas was for a 40-day truce during which Hamas would free around 40 hostages - including women, those under 19 or over 50 years old, and the sick - in return for around 400 Palestinian detainees at a 10-for-one ratio.
Israel would reposition its troops outside of settled areas. Gaza residents, apart from men of fighting age, would be permitted to return home to areas previously evacuated, and aid would be ramped up, including urgent equipment to house the displaced.
But the offer appears to stop short of Hamas's main demands in earlier talks - that a ceasefire include a commitment for a permanent end to the war and Israeli withdrawal.
It also does not cover the release of Israeli hostages who are soldiers or healthy men of fighting age, or a Hamas demand for as many as 1,500 detainees to be freed.
Delegations from Hamas and Israel are both in Qatar this week discussing details of the ceasefire.
'TOO MANY INNOCENT' KILLED, BIDEN SAYS
Biden told NBC that Israel risked losing international support unless it takes more steps to spare civilians. Israel has threatened to attack Rafah, the last city on the southern edge of the Gaza Strip, where more than half of its 2.3 million residents are hemmed in, most sleeping rough in makeshift tents or public buildings.
"There are too many innocent people that are being killed. And Israel has slowed down the attacks in Rafah," Biden said, adding that Israel had committed to make it possible for Palestinians to evacuate from Rafah before intensifying its campaign there.
Israeli Prime Minister Benjamin Netanyahu rejected as "delusional" an earlier Hamas counter-offer for a ceasefire during which all hostages would go free, Israel would withdraw its troops from Gaza and an agreement would be reached on an end to the war.
It says it will not halt the war until Hamas is eradicated.
On Monday, Netanyahu repeated his description of Hamas's demands as "from another planet" and said it was up to the group to decide whether to accept Israel's latest offer.
On NBC, Biden said that a temporary ceasefire would jumpstart a process for Palestinians to have their own state. Netanyahu has rejected an independent Palestinian state as incompatible with Israel's need for full security control of all land between the Jordan river and Mediterranean Sea.
Hamas killed 1,200 people and captured 253 hostages on Oct. 7, by Israeli tallies, triggering a ground assault on Gaza, with nearly 30,000 people confirmed killed, according to Gaza health authorities.
In Gaza, there were mixed feelings about the prospect of a truce that might stop short of a permanent end to the war.
"We don't want a pause, we want a permanent ceasefire, we want an end to the killing," Mustafa Basel, a father of five from Gaza City, now displaced in Rafah, told Reuters.
"Unfortunately, the people's conditions are so grim that some may accept a pause, even (just) during Ramadan. People have mixed feelings, they want a permanent end to the war but the dire conditions make them want a pause even for a month or 40 days in the hope it becomes permanent."
