WASHINGTON » In an intensifying diplomatic effort, U.S. Secretary of State John Kerry is making a major push to secure what Obama administration officials are calling a "framework" accord that would be a critical first step to a comprehensive Middle East peace agreement. But critics are already branding it as an effort to play for time.

Kerry leaves Wednesday for Jerusalem, on the first of what are expected to be repeated trips to the region in January and February. His goal is to secure the framework agreement quickly, before his target of April-end for completing a comprehensive peace treaty.

The framework document is aimed at achieving enough of a convergence on core issues that the two sides can begin to make headway toward a formal peace agreement, leading to an independent Palestinian state. The document is expected to be short, perhaps fewer than a dozen pages and without detailed annexes. It would not be signed by Israeli and Palestinian leaders and would likely take note of reservations the two sides have about some elements, U.S. officials said.

U.S. officials are, nonetheless, hopeful that it will provide some impetus to the fraught talks.

"Once they have a shared vision of what that will look like, then it will become easier to finalize the details," said a senior U.S. State Department official, who asked not to be identified under the agency’s ground rules.

The core issues to be resolved include the borders between Israel and a future Palestinian state, the status of Jerusalem as a possible capital for the new state as well as Israel, Israel’s insistence that its identity as a Jewish state be recognized and the Palestinians’ demand that refugees should have the right to return to their former homes. Another issue will be determining security arrangements in the West Bank, including the role of Israeli forces in the Jordan Valley.

The agreement might be made public to prepare Israelis and Palestinians for what a potential peace treaty might look like, although no final decision has been made. So far there have been 20 rounds of closed talks between the Israelis and the Palestinians. The United States has asked both sides to keep the details confidential.

Critics said the move was mainly a stalling maneuver and a way to institutionalize the negotiating process, so that it could continue beyond the nine-month timeline that Kerry set last summer for completing a peace treaty.

"It is clear that Kerry cannot get a comprehensive ‘final status agreement’ in his nine-month timetable, so now he appears to be looking at a ‘framework agreement’ instead," said Elliott Abrams, who was a senior official in President George W. Bush’s national security council.

"I don’t think it will work," added Abrams, who asserted that the two sides would not make wrenching and unpopular compromises for the sake of a "piece of paper" that fell short of an actual peace treaty.

Kerry did not mention the need for a "framework" accord when the peace talks resumed in July after a long hiatus.

But in the fall the United States broached the notion of a "framework" accord between the Israelis and the Palestinians, and President Barack Obama later mentioned the idea in an appearance at the Saban Center for Middle East Policy at the Brookings Institution. "It is possible over the next several months to arrive at a framework that does not address every single detail but gets us to a point where everybody recognizes, better to move forward than move backwards," Obama said.

In Israel, where the U.S. goal of a framework agreement has been debated for weeks, there are conflicting views.

Gilead Sher, a former Israeli peace negotiator and chief of staff to former Prime Minister Ehud Barak, said the framework agreement was the most that the United States could accomplish at this point, but still an important step forward after years of little progress.

"The question is how substantive such an agreement will be," said Sher, who is also the co-chairman of Blue White Future, which advocates the evacuation of some Jewish settlers from the West Bank. "That’s my big question mark on the whole concept. But having a framework agreement is better than nothing."

Daniel Levy, the British-based director of the Middle East and North Africa program at the European Council on Foreign Relations, said the framework idea amounted to "going backwards."

"We’re well past the time for constructive ambiguity," said Levy, a left-leaning British-Israeli who has long worked on the peace process for various research organizations. "Any framework agreement would have to have a significant degree of clarity in order to reverse that trend."

The Palestinians are poised to seek recognition in the International Criminal Court and U.N. bodies if the talks fail.

However, Saeb Erekat, the chief Palestinian negotiator in the talks, told reporters this month that the Palestinians would "absolutely" be willing to continue negotiations beyond April if there were a framework agreement by then.

"If we reach a framework agreement that specifies the borders, the percentage of swaps, the security arrangements, the Jerusalem status, refugees — then that is the skeleton," Erekat said.

Zakaria al-Qaq, a Palestinian expert in national security at Al-Quds University in East Jerusalem, was more skeptical.

"The framework idea is like reinventing the wheel," he said. "It is buying time without a solution, extending the negotiations for another year."

Kerry, who will be making his tenth trip to the Middle East as secretary of state, will arrive after a tense week, in which Israel released a third batch of long-serving Palestinian prisoners; Israel twice bombed the Gaza Strip after rockets from there penetrated its territory; a bus bombing was thwarted in a Tel Aviv suburb; and conservative Israeli ministers moved a bill forward to annex parts of the West Bank, prompting Palestinian outrage.

Kerry has repeatedly said that time is not an ally, and now the instability in the region appears to be adding to his sense of urgency. Even tackling a framework will prove very challenging, some experts said.

"What they are trying to do now is one of the hardest parts: getting both sides to reveal their bottom line on the core issues," said Robert M. Danin, a former State Department official who worked on Middle East issues. "It is both ambitious, but necessary if you are going to have a real, conflict-ending peace agreement."