US Secretary of State John Kerry said Tuesday that both Israelis and Palestinians were responsible for the current crisis in peace talks, but appeared to allocate the lion’s share of the blame to Jerusalem.

At the same time, he expressed hope that the two sides would continue to negotiate, but also warned that there was a “limit” to how much effort the US government could invest in the process if the two parties weren’t serious about negotiating a pact.

“Both sides wound out in a position of unhelpful moves,” Kerry said at a hearing of the Senate Committee on Foreign Relations, delineating what he said led to the current impasse.

“The prisoners were not released by Israel on the day they were supposed to be released and then another day passed and another day, and then 700 units were approved in Jerusalem and then poof — that was sort of the moment,” Kerry said.

The secretary of state was referring to the planned fourth release of Palestinian security prisoners, which was originally slated for March 29. Israel did not proceed with the release on time, with Jerusalem saying that it was delayed because the Palestinian Authority had demanded that Israeli Arabs be among those freed and was unwilling to commit to extend peace talks beyond their April 29 deadline.

On April 1, the Israel Lands Authority reissued a call for tenders for 708 homes in the East Jerusalem neighborhood of Gilo, which is located beyond the 1967 lines and was annexed by Israel.

Later that same day, PA President Mahmoud Abbas signed 15 letters of accession to multilateral treaties and conventions, in what Israel said was a clear breach of Ramallah’s commitment not to take unilateral steps to advance their statehood bid so long as the talks were ongoing.

“The treaties were unhelpful, and we made that crystal clear to the Palestinians,” Kerry said at the Senate hearing.

He also said that Palestinians recognition of Israel as a Jewish state should be part of a final peace agreement, but added that the step would likely only be achieved at the very end of the process and not at the outset. Prime Minister Benjamin Netanyahu has in recent months elevated the demand for such Palestinian recognition to that of a core issue.

Despite his evident frustration, Kerry said it was still possible for the two sides to find a way to extend the talks and return to “substantive discussion.”

Senator John McCain told Kerry that “talks, even though you might drag them out for a bit, are finished,” but the secretary of state replied by saying that the peace process should not be declared dead as long as the two sides declare their willingness to continue negotiating.

At the same time, Kerry said, “there are limits to the amount of time the president and myself can put into this, considering the other challenges around the world, especially if the parties can’t commit to being there in a serious way.”

Afterward, the State Department attempted to dispel the impression that Israel had been singled out for harsher criticism in Kerry’s comments.

“As he has been throughout this impasse, today Secretary Kerry was again crystal clear that both sides have taken unhelpful steps and at no point has he engaged in a blame game,” spokeswoman Jen Psaki said.

“Today he even singled out by name Prime Minister Netanyahu for having made courageous decisions to bring the process this far. Now it is up to the parties and their leaders to determine whether we maintain a productive path,” she added.

Kerry was set to meet US President Barack Obama and Vice President Joe Biden in the Oval Office later Tuesday to discuss the fate of the peace talks.

Senior officials have rejected the idea that Obama intends to pull the plug on the peace effort, and say he deeply appreciates his top diplomat’s efforts.

But equally, Obama may need to be convinced that Kerry’s intense focus on the initiative is merited given its apparently slim chance of success and deepening global crises crying out for US attention elsewhere.

“The issue now is whether the parties can demonstrate that they are willing to make the difficult decisions necessary to move the process forward,” said White House spokesman Jay Carney.

“The parties understand what the choices are and they understand that these are not decisions that the United States or any other country can make. The parties themselves have to make them.”

On Wednesday, Kerry will meet with Foreign Minister Avigdor Liberman in Washington.

AFP contributed to this report.