Jordanian demonstrators shout anti-Israel and anti-U.S. slogans during a rally to support Jordan and Palestine, rejecting U.S. Secretary of State John Kerry's peace talks, in Amman, Jordan, on Friday. (Mohammad Hannon/AP)

— The Obama administration sought Friday to keep peace talks between Israel and the Palestinians from falling apart over Israel’s refusal to free about two dozen Palestinian prisoners, who were scheduled to be released Saturday.

“The Israeli government has informed us through the American mediator that it will not abide with its commitment to release the fourth batch of Palestinian prisoners scheduled for tomorrow,” Palestinian spokesman Jibril Rajub told the AFP news agency.

On Saturday, Palestinian Minister of Prisoner Affairs Issa Qaraqae told the AFP news service in Ramallah that “there are efforts to solve the crisis and I believe that in 24 hours everything will be clearer.” He said it was still possible that the prisoners would be released “maybe in the coming days.”

Palestinians have threatened to walk out of talks with a month to go before an unofficial deadline for an outlined peace deal if Israel reneges on the release of longtime prisoners, including several convicted of terrorist crimes against Israelis.

Secretary of State John F. Kerry and U.S. negotiators are trying to prevent a Palestinian walkout, either by securing an Israeli pledge to carry out the release or by brokering a new compromise that would extend talks.

The Palestinian Authority had agreed to shelve plans to seek further statehood recognition through the United Nations during nine months of fast-track talks brokered by Washington.

In exchange, Israel agreed to release 104 prisoners whose imprisonment since before the 1993 Israeli-Palestinian agreement known as the Oslo accords is a rallying cry among Palestinians protesting Israeli occupation and police tactics.

Israel has released 78 prisoners in three groups.

The final group was always assumed to be the hardest for Israel to release, because many convicted of the worst crimes were left for last and because of heavy opposition to the move within Israeli Prime Minister Benjamin Netanyahu’s right-leaning political coalition.

Israeli cabinet members had warned they would block the final release if the Palestinians refused to extend the talks beyond their April 29 deadline. Israeli hardliners also said the talks had failed to make progress and accused Palestinians of dragging their feet.

Kerry spoke to Netanyahu on Thursday and again Friday. Kerry also met with Palestinian Authority President Mahmoud Abbas in Amman, Jordan, on Wednesday.

Kerry traveled to Saudi Arabia on Friday with President Obama for largely unrelated discussions with Saudi King Abdullah. Kerry’s chief negotiator, former ambassador to Israel Martin Indyk, met with Abbas at his West Bank headquarters on Thursday and was shuttling between there and Jerusalem.

“At the beginning of these negotiations, the Palestinians agreed to not undertake action at international organizations, and the Israelis agreed to release a number of pre-Oslo prisoners,” State Department spokeswoman Jen Psaki said as Kerry flew to Riyadh. “Ambassador Indyk and Secretary Kerry are still working intensively with the parties on these issues.”

She refused to discuss specifics.

The two sides agreed to resume long-stalled talks in the summer, under heavy pressure from Kerry. Netanyahu and Abbas had agreed only to remain at the table until the end of April.

With that deadline only a month away, it seems likely that if negotiations survive this impasse, they would then be extended at least for several more months. Kerry has already scaled back his goal of a full peace deal by the end of April and is now seeking a detailed outline that would be filled in with further talks.

The outline, or framework agreement, is effectively on hold over a separate dispute. Israel wants the Palestinians to agree now that they will recognize Israel as a “Jewish state,” alongside their own future Palestinian one. Palestinians have so far refused, arguing that such recognition could prejudge the rights of Palestinians who left or were evicted from what is now Israel. The also complain that the Jewish state issue is a sideshow to the main tasks of setting borders and resolving long-standing disputes over the status of Jerusalem and refugee rights.

The Palestinian leadership was considering what to do next and was under domestic political pressure to walk out and boycott further negotiations with Israel in favor of efforts to gain a kind of de facto statehood through membership in international bodies.

The United States and Israel strongly oppose those Palestinian attempts, which have been successful so far, for fear that Palestinians could use them to bring international legal and human rights cases against Israel.

Rajub, the Palestinian spokesman, called the Israeli move a “slap in the face of the U.S. administration and its efforts” and said the Palestinians would resume their international diplomatic efforts.

Kerry opted against immediate in-person diplomacy with either leader. He flew to Europe on Saturday and may meet with Russia’s foreign minister about Ukraine, Psaki said. The White House had announced Friday that the two diplomats would meet soon to try to defuse the crisis over Ukraine.

Kerry has acted as his own chief negotiator throughout the eight months of talks, speaking directly to Netanyahu and Abbas.

Although Kerry insists that talks are productive, his task was made harder by brinksmanship on both sides over the prisoner issue.

If talks continue, one option is that the release is postponed to coincide with Kerry’s original deadline of an agreement by the end of April.

Palestinians argue that they have already negotiated the prisoner release and should not have to make a further deal about timing just to keep talks going.

If Abbas agrees to any delay it is assumed he would ask for additional concessions from Israel, something the United States could help broker.

While the two sides are negotiating, Abbas agreed not to seek redress at the United Nations, where Palestine won “non member observer state” status in 2012. Full membership to the U.N. was blocked to Palestinians in 2011.

Kerry’s main argument against a Palestinian return to the U.N. has been that it is a only short-term fix. Palestinians stand to lose a chance at full statehood and lasting peace, along with much U.S. support, if they press ahead, he says.

To the Israelis, the U.S. argument to keep talking is that the alternative is worse. The United States cannot prevent further strengthening of Palestinian independence at the U.N. and can’t put up much argument against it if this attempt at diplomacy fails, U.S. diplomats say.

William Booth in Jerusalm contributed to this report.