RAMALLAH (Ma’an) -- President Mahmud Abbas said Thursday that the Palestinian leadership was sparing no effort to liberate Palestinian prisoners from Israeli jails.

Speaking with prisoners’ families at a sit-in tent in Al-Bireh, Abbas said that the prisoners’ cause is not only political but also a humanitarian issue.

"This is another reason to say that if anything happens to our prisoners, we will not be silent," Abbas said.

He stressed that even if every other issue in the peace process is resolved, the Palestinians will not make an agreement until every prisoner is released from Israeli jails.

Meanwhile several protesters held signs and chanted slogans criticizing the PA's inaction and calling for Abbas to do more for the hunger-strikers.

Also Thursday, Abbas met with the United Nations envoy for the Middle East peace process to discuss the issue of Palestinian prisoners, a UN official said.

Robert Serry and Abbas met in Ramallah and discussed "issues of shared interest," including peace talks and the internal politics, a spokesman for the UN official said.

"In this context, there was a focus on the issue of Palestinian prisoners," Richard Miron said.

Abbas and Serry agreed on the urgency of resolving the issue immediately, Serry's office said, and the president expressed his appreciation for the United Nations' contribution.

Serry reiterated the concern of the UN, expressed a day earlier by UN chief Ban Ki-moon, who stressed "the importance of averting any further deterioration in their condition."

"(Ban) reiterates that those detained must be charged and face trial with judicial guarantees, or released without delay," he said through a spokesman Wednesday.