Top US officials have promised to pressure Israel to release 26 long-term Palestinian prisoners, an official Palestinian source said Monday.

The promise was made to Palestinian President Mahmoud Abbas as the US intensifies its efforts to avoid a collapse of the faltering peace talks.

In a telephone conversation on Monday, Abbas and US Secretary of State John Kerry discussed the issue of Palestinian prisoners and ways to revive the peace process.

Kerry's phone call came during Abbas' meeting with the US Special Envoy for Peace, Martin Indyk, in the Jordanian capital of Amman, the source told Xinhua.

"Abbas discussed with Kerry and Indyk the US proposals to push the peace process forward," the official said.

Kerry and Indyk told Abbas the US would pressure Israel to release 26 long-term Palestinian prisoners in Israeli jails who are supposed to be freed later this month.

According to the Palestinian official source, the US is now intensifying its efforts to avoid a collapse of the Palestinian- Israeli peace talks it has been mediating since last July. He added the US has proposed to extend the negotiations, which are set to end late in April.

When the peace talks between the two sides resumed in July, Israel originally agreed to release 104 prisoners chosen by an Israeli ministerial committee. Seventy-eight prisoners have been freed so far.

Israeli officials say if the Palestinians refuse to extend the peace negotiations, the remaining prisoners will not be released.

However, the Palestinians reject linking the prisoners' release with the extension of the peace negotiations, and threaten to approach international organizations to sue Israel for not meeting its commitments.

The US peace plan proposed by Kerry tackles final status issues including the borders of the future Palestinian state, Palestinian refugees, security and the contested status of Jerusalem, claimed by both as their capital.

However, peace talks have not witnessed any progress as grave differences on core issues continue to drive a wedge between the two sides.