US President Joe Biden said he hoped the temporary truce between Israel and Hamas can go on as long as hostages are being released, after Hamas freed 17 more people.

According to international media reports, Hamas said it wanted to extend the pause in fighting, which will enter its fourth day and final agreed day on Monday, if serious efforts were made to increase the number of Palestinian detainees released by Israel.

Thirty-nine teenage Palestinian prisoners were released by Israel on Sunday, taking the total since the truce began to 117.

Hamas said it had handed over 13 Israelis, three Thais and one with Russian citizenship, and the International Committee of the Red Cross confirmed it had successfully transferred them from Gaza on Sunday.

Omar Abdullah Al Hajj, 17, one of the Palestinian detainees released Sunday, said he’d been kept in the dark about what was happening in the outside world.

“I can’t believe I’m free now but my joy is incomplete because we still have our brothers who remain in prison, and then there is all the news about Gaza that I am having to learn about now,” he told reporters.

The latest three Thai hostages released were in good health, Thailand’s prime minister said.

Efforts to free the remaining 15 Thais held would continue, the Ministry of Foreign Affairs said. Sunday’s hostage release follows the liberation of 13 Israelis and four foreigners on Saturday.

The deal survived an earlier threat when Hamas said on Saturday it was delaying hostage releases until Israel met all truce conditions, including committing to let aid trucks into northern Gaza.

Qatari diplomats are now on site in Gaza to supervise the entry and delivery of their country’s aid, Qatar’s Foreign Ministry said.

A UN official who took part in a humanitarian convoy to northern Gaza said on Sunday aid groups were on track to deliver the biggest shipment in over a month, describing thin, gaunt residents slaking their thirst as soon as water arrived.

“People are so desperate and you can see in adults’ eyes they haven’t eaten,” the UN children’s agency’s James Elder told reporters from southern Gaza after returning from Gaza City.

Even as the aid deliveries flowed north, Elder said he saw hundreds of Gazans heading in the other direction, fearing the renewal of Israeli bombardments if the four-day truce is not prolonged.

“People are so terrified that this pause won’t be continued,” he said.