President Biden and the leaders of 17 countries whose citizens were abducted by Hamas issued a joint statement Thursday calling on the group to accept a hostage deal currently on the table that would lead to a ceasefire in Gaza.

Why it matters: This is the most significant joint statement the international community has published since Oct. 7 pressuring Hamas to release the hostages.

• The statement was signed by Biden and the leaders of Argentina, Austria, Brazil, Bulgaria, Canada, Colombia, Denmark, France, Germany, Hungary, Poland, Portugal, Romania, Serbia, Spain, Thailand and the United Kingdom.

Behind the scenes: A senior U.S. official said in a briefing call that the idea to publish the joint statement came up during a meeting between White House national security adviser Jake Sullivan and family members of American hostages about two weeks ago.

What they're saying: "We call for the immediate release of all hostages held by Hamas in Gaza for over 200 days. 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 18 leaders said in the statement.

• They emphasized that the deal on the table "would bring an immediate and prolonged ceasefire in Gaza, that would facilitate a surge of additional necessary humanitarian assistance to be delivered throughout Gaza, and lead to the credible end of hostilities."
• "Gazans would be able to return to their homes and their lands with preparations beforehand to ensure shelter and humanitarian provisions", the statement said.

Zoom in: The senior U.S. official said that the fighting continues because the leader of Hamas in Gaza, Yahya Sinwar, refuses to release the hostages — especially women, men above the age of 50 and male hostages under the age of 50 who are in bad medical condition.

• "Justice will be done with Sinwar," the U.S. official said.
• The official said there has been progress in talks over the last few months with Hamas leaders outside Gaza, but that Sinwar — the main decision-maker — has rejected the deal and insisted on keeping the hostages rather than achieving a ceasefire.
• "This is the truth about what is happening," the U.S. official stressed.
• The U.S. official noted that the deal on the table allows for an unhindered return of Palestinians to the northern Gaza Strip when conditions permit.
• He said the deal is structured in a way that would require a ceasefire for Palestinians to be able to travel to the north, with the goal of ensuring certain conditions are met — including shelter, UN inspection and sufficient aid.
• "When the conditions are ready, people will return," the U.S. official said.

What's next: The U.S. official said that the Biden administration and the mediators — Qatar and Egypt — received signals from Hamas in the last few days that the group did not intend to reject the deal and is ready to sit down at the negotiating table.

• "We will see in the coming days if they are serious. We have some indications that it may be possible to move forward, but we are not sure because we hear things from Hamas leaders abroad that do not always represent the position of Hamas leaders inside Gaza," the U.S. official said.