Palestinians lined up for food during the ongoing Israeli bombardment of the Gaza Strip in Rafah on Monday, Nov. 13, 2023. AP
"The surge in humanitarian relief, the surge in fuel, the pause... will come when hostages are released," Brett McGurk told a security conference in Bahrain.
Release of a large number of hostages would result in "a significant pause... and a massive surge of humanitarian relief," he said.
The Palestinina resistance groups captured about 240 captives on October 7, during Al-Aqsa Flood operation on Gaza envelope.
McGurk said Biden had discussed the issue on Friday evening with the Emir of Qatar, which is leading mediation efforts towards a ceasefire and release of the people detained in Gaza.
On Friday, the White House said Biden and Qatar's Emir Sheikh Tamim bin Hamad discussed the urgent need for all captives held by Hamas to be released without further delay.
Two days earlier Biden had said he was "mildly hopeful" of reaching a deal to free them.
So far efforts by Qatar have led to the release of four of them and Israel's army said this week it had recovered the bodies of two women others.
McGurk said on Saturday that the situation in the besieged Palestinian territory was "horrific" and "intolerable".
Israel has refused to heed calls for a ceasefire or for "extended humanitarian pauses" as stipulated by the UN Security Council resolution, voted on Wednesday.
Jordanian Foreign Minister Ayman Safadi, who also attended the Bahrain conference, said it was "unacceptable" to link humanitarian pauses to a captive release.