WASHINGTON (AFP) -- US Secretary of State John Kerry is moving cautiously and smartly towards fresh Middle East peace talks, but deep distrust between all sides means success is far from guaranteed, analysts say.

Wresting an important concession from Arab League nations on Monday that land swaps could be on the table in any deal between Israel and the Palestinians, is one sign of a new seriousness to resume the negotiations.

But on a path littered by decades of failures and dashed hopes, Kerry needs to tread carefully towards the US-avowed goal of a two-state solution of Israelis and Palestinians living side-by-side.

Since taking up his post on February 1, the new top US diplomat has plunged into the quagmire of the Israeli-Palestinian peace talks which collapsed in late 2010, vowing to pursue "a quiet strategy" to revive them.

"Getting them to the table is one thing, keeping them there is another... he clearly wants to figure out some concept to keep them at the table," Aaron David Miller, vice president of the Wilson Center's Middle East program, said.

Kerry seems to be focusing his efforts on "multiple building blocks," Miller told AFP, including an effort to boost economic development in the West Bank, a push to bring other Arab nations on board and a bid to ensure Israeli security.

"So it's smart to be creating these building blocks, there's no question about that. But there will be a moment where someone is going to ask to see a line on a map and there will be the so-called proverbial moment of truth."

On Monday an Arab League delegation met with Kerry far from prying eyes to discuss reviving a decade-old Arab Peace Initiative.

Under the original 2002 Saudi-led plan, the League's 22 members would forge full diplomatic relations with Israel in exchange for "total withdrawal by Israel to the June 4, 1967 lines" and the establishment of a Palestinian state.

But after the talks, Qatari Prime Minister Sheikh Hamad bin Jassem Al-Thani, who headed the delegation, announced the Arab League recognized the need for a "comparable and mutual agreed minor swap of the land" to reflect the changing demographics on the ground.

Kerry hailed the surprise move as a "very big step forward."

"If the Palestinians and Israelis reach a final status agreement between them then -- 22 Arab countries and 57 Muslim countries -- all of them have agreed, number one, that they would consider the conflict ended," Kerry said.

But much remains to be decided, including the size of the land swaps, as well as the most difficult issues such as borders, security, the return of Palestinian refugees and the fate of Jerusalem claimed by both as their capital.

"I would not say it is a major breakthrough," said Salman Shaikh, director of the Brookings Doha Center, describing it more as "an expression of goodwill."

"It all depends again on the Israeli positions whether we really see any kind of movement or breakthrough there."

The Arab League pronouncement was initially hailed by Israeli chief negotiator, Tzipi Livni, due to hold talks with Kerry in Washington on Thursday, as "very good news," although another official was much cooler.

And chief Palestinian negotiator Saeb Erakat played down the significance, saying: "This is not something new."

However, Hussein Ibish, senior fellow at the American Task Force on Palestine, said the statement answered "a long-standing Israeli concern about the Arab Peace Initiative which is that it is a diktat or a 'take it or leave it offer.'"

It shows the API "is a set of ideas that can be worked with. And if there are elements that the Israelis want clarification on, or there are parts of it that need to be expanded or filled in ... that is entirely possible."

While Kerry appeared to be newly empowered to take up the peace process, Ibish cautioned the two sides remained "enormously" far apart.

Miller agreed, arguing it was far from clear if al-Thani was speaking on behalf of all the Arab League, or indeed exactly what he meant.

"Who knows what the lag is going to be between the statement in Washington... and the realities of recasting the Arab initiative in the Arab League as a whole? Which is why I do not understand why Kerry is crowing about this."

He cautioned the Israelis would have a vastly different interpretation of land swaps, warning about the "Israelis putting their own spin on this" and then "the whole thing is going to be toast before it's useful and productive."

There were "very likely to be very discordant positions on borders and security... we're talking here about months and months of negotiations," said Miller, who has advised six secretaries of state on Middle East peace.

"I don't think the skepticism about the prospects of an agreement has ever been stronger in the past 20 years," added Ibish. "On both sides people want it, but I don't think they've ever believed in it less."