U.S. Secretary of State John Kerry on Monday issued a stark warning to Israel to resume long-stalled peace talks with the Palestinian Authority, saying that if efforts fail now they may never get another chance.

“We are running out of time. We’re running out of possibilities… If we do not succeed now, we may not get another chance,” Kerry told a forum held by the American Jewish Community, according to the AFP news agency.

Kerry’s warning came amid reports that he is planning to return to the Middle East region within days, for his fifth trip to Israel since he launched his bid to kickstart the negotiations in early February.

“We can’t let the disappointments of the past hold the future prisoner. We can’t let the absence of peace become a self-fulfilling prophecy,” the top U.S. diplomat urged in one of his most passionate speeches to date on the search for peace.

“The absence of peace becomes perpetual conflict,” he stressed, urging the Jewish forum to reflect on what will happen if his peace bid does not work.

“We will find ourselves in a negative spiral of responses and counter-responses, that can literally slam the door on a two-state solution, having already agreed, I think, that there isn’t a one-state one,” Kerry said, according to AFP.

“And the insidious campaign to de-legitimize Israel will only gain steam,” he said, hinting that any refusal by Israel to come back to the negotiations could lead it to losing global friends as the PA pursues its unilateral statehood bid through international bodies such as the United Nations.

The only way forward was to work towards a two-state solution, Kerry said, stressing that while the United States “will always have Israel’s back,” it would be even better “if we had some more company.”

“I assure you that a stable Palestinian state with assured borders and a flourishing economy will only strengthen Israel’s security and Israel’s future,” AFP quoted him as having said.

“Resolving this conflict for both sides can have far-reaching benefits that will be in everybody’s interests. And the reverse is also true. Not resolving this will result in serious consequences for both.”

While he acknowledged that there was deep-rooted skepticism and even cynicism, he said everyone must seize the opportunity ahead.

“What makes this different from every other time? The difference is that what happens in the coming days will actually dictate what happens in the coming decades,” Kerry warned.

The peace talks between Israel and the PA broke down in 2010, but not because of Israel. The talks broke down because PA Chairman Mahmoud Abbas refused to negotiate with Israel even though it agreed to his precondition and froze construction in Judea, Samaria and eastern Jerusalem for 10 months. Instead, he has continued to impose preconditions on talks with Israel.

In recent weeks, Kerry has been pushing the sides to resume peace talks, and recent reports indicated that he has proposed that Israel freeze construction east of the 1949 armistice line so the talks can resume.

It was not clear if Prime Minister Binyamin Netanyahu responded favorably to Kerry’s suggestion of a new construction freeze.

As part of his efforts to lure the sides back to the negotiating table, Kerry unveiled a plan to boost the Palestinian Authority’s economy by attracting $4 billion in private investment.

Kerry said the plan could transform the lives of PA Arabs, adding it was also imperative to create jobs and meet the hopes of young people for a better economic future.

Israel has not officially responded to the plan, but it was given a cool reception by the PA, which stated that it would “not offer political concessions in exchange for economic benefits.”