The leaders of 17 countries, including the United States, released a joint statement Thursday morning calling for Hamas to release the remaining hostages taken in the group’s Oct. 7 attack on Israel.

The countries that signed on to the statement all have citizens being held in the Gaza Strip. They also include Argentina, Austria, Brazil, Bulgaria, Canada, Colombia, Denmark, France, Germany, Hungary, Poland, Portugal, Romania, Serbia, Spain, Thailand and the United Kingdom.

“We call for the immediate release of all hostages held by Hamas in Gaza for over 200 days,” the statement reads. “They include our own citizens. The fate of the hostages and the civilian population in Gaza, who are protected under international law, is of international concern."

The leaders emphasized that, as part of a deal on the table that Hamas has so far rejected, a hostage release would bring “an immediate and prolonged cease-fire in Gaza” that would help humanitarian aid reach the territory. 

Gazans would be able to return to their homes following preparations aimed at ensuring shelter and humanitarian assistance, the statement adds.

"We strongly support the ongoing mediation efforts in order to bring our people home," the world leaders said. "We reiterate our call on Hamas to release the hostages, and let us end this crisis so that collectively we can focus our efforts on bringing peace and stability to the region."

When Hamas struck Israel, militants took about 250 hostages. More than 100 of the hostages were released in November as part of a temporary cease-fire that also freed 240 Palestinian prisoners held in Israel.

Khalil al-Hayya, a top Hamas political official, told The Associated Press on Wednesday the group does not know exactly how many hostages remain in Gaza and are still alive.

A senior U.S. administration official called the statement “quite extraordinary,” noting that earlier attempts had been unsuccessful. 

The official said a cease-fire would begin if Hamas released just women, elderly, wounded and sick hostages. Negotiations for a truce, however, have stalled. 

“We have worked it out in meticulous detail and Hamas has rejected that,” the official said. “And because of that, we still have fighting ongoing in Gaza and we’re working other dimensions to the crisis every single day. But the key really is the hostages.”

Hamas released a hostage video Wednesday showing Hersh Goldberg-Polin, an Israeli-American man, the first sign he is still alive since Oct. 7. Goldberg-Polin, 23, was abducted from the Tribe of Nova music festival. 

In the video, Goldberg-Polin is missing part of his left arm.

Witnesses said he lost it when attackers tossed grenades into a shelter where people had taken refuge.

The senior official said the U.S. is analyzing the video.

The Associated Press contributed to this report.