President Barack Obama's Mideast envoy finds himself increasingly hamstrung, with Israel's foreign minister on Thursday all but ruling out a peace deal for years to come and the Palestinian leader weakened by his decision not to push for a Gaza war crimes tribunal against Israel.

Jordan's King Abdullah II added a gloomy warning that prospects for peace are "sliding into darkness."

Obama envoy George Mitchell, visiting Israeli and Palestinian leaders for the second time in three weeks, is trying relentlessly to bring the sides together for talks, but the obstacles he faces are daunting.

Foreign Minister Avigdor Lieberman suggested that the two sides come up with a long-term interim arrangement that would ensure stability, while at the same time putting off a final deal. He recommended leaving the toughest issues — such as the status of disputed Jerusalem and a solution for Palestinian refugees who lost homes amid war — "to a much later stage."

"Anyone who says that within the next few years an agreement can be reached ending the conflict ... simply doesn't understand the situation and spreads delusions, ultimately leading to disappointments and an all-out confrontation here," Lieberman told Israel Radio.

Lieberman's suggestion will not necessary translate into policy, which is set by Prime Minister Benjamin Netanyahu. Netanyahu's office wouldn't comment when asked if Lieberman's comments reflected his opinion. But other senior Netanyahu confidants share similarly skeptical views on peacemaking.

Lieberman's approach runs counter to U.S. efforts to reach an Israeli-Palestinian peace deal quickly. The Palestinians have said they will not agree to an interim peace deal that would put off a resolution of the conflict indefinitely.

In Washington, State Department spokesman Ian Kelly said Thursday that restarting negotiations is an urgent matter. "The time has come for both sides to agree to just cut right through all of this and get back to peace talks," he said.

On the Palestinian side, Israel's punishing winter offensive in Gaza deepened anger toward Israel and further reduced whatever sentiment there was for concessions to Israel in a peace deal. It also underlined Palestinian President Mahmoud Abbas' powerless position in Gaza, overrun by Hamas militants in 2007.

Abbas is walking a tightrope, trying not to appear intransigent to the White House while seeking to retain credibility with Palestinians accusing him of appeasing the Israelis.

On Wednesday, Gaza professors threw shoes at his defaced image and West Bank commentators called for his resignation, signs Abbas may have miscalculated in bowing to what Palestinian officials say was intense U.S. pressure to suspend Palestinian diplomatic efforts to get Israeli officials put on trial for war crimes in Gaza.

Nearly 1,400 Palestinians were killed in the war, including hundreds of civilians. Israel, which lost 13 civilians and soldiers in the war, launched the campaign to end years of Hamas rocket fire on Israeli border towns.

A 575-page U.N. report about the fighting alleges that both Israel and Hamas committed war crimes, something both sides deny.

Mitchell is due to hold separate meetings with Netanyahu and Abbas on Friday.

On his last trip, Mitchell failed to get them to the negotiating table. Abbas insisted that Israel halt all construction in West Bank settlements before talks could resume, but Netanyahu refused to make such a commitment.

Though Abbas and Netanyahu later attended a three-way meeting with Obama on the fringes of the United Nations General Assembly in New York, the two sides remain far apart.

Jibril Rajoub, a leading member of Abbas' Fatah movement, told reporters on Thursday that Abbas would tell Mitchell again when they meet that the Palestinians will not resume talks unless Israel freezes settlement construction.

Jordan's king was interviewed by the Israeli Haaretz daily, which planned to run the full text on Friday. In an excerpt on its front page Thursday, the paper quoted Abdullah as saying "We are sliding back into the darkness" because of lack of movement toward peace.

Despite the gloomy atmosphere, Mitchell said Thursday he believes in his mission.

"President Obama ... and the U.S. government remain deeply and firmly committed toward achieving a comprehensive peace," he told reporters as he arrived for a meeting with Israeli President Shimon Peres. "They believe there is no alternative to that if all the people of the region are to be able to live in peace."