JERICHO, West Bank (AP) — Israel's demand to keep control of the West Bank's Jordan Valley for 40 more years in the event of a peace deal is driven by economic interests, not security concerns, the chief Palestinian negotiator said Thursday.

Saeb Erekat made the comments during a tour of the valley for foreign diplomats and reporters. The Palestinians view the sparsely populated area, which borders Jordan, as the breadbasket of their future state, while Israel considers it a security buffer.

Israeli-Palestinian negotiations on the terms of a Palestinian state resumed last month, and both sides promised U.S. Secretary of State John Kerry not to discuss the content of the negotiations for the time being.

However, Palestinian officials close to the talks have said Israel proposed to keep control of the valley and of West Bank border crossings with Jordan for 40 years after a Palestinian state is established.

The Palestinians seek a state in the West Bank, Gaza Strip and east Jerusalem, lands Israel captured in the 1967 Mideast war.

The Erekat-led tour started out in the valley's Palestinian-run town of Jericho, where he lives, and headed north, passing a string of Israeli farming settlements where dates, flowers, herbs and other produce are grown for export.

Erekat claimed that Israeli settlements in the valley had an estimated income of $612 million in 2012, but did not say what the figure was based on.

He didn't refer specifically to Israeli demands in the negotiations, but said that Israeli Prime Minister Benjamin Netanyahu has called for keeping the valley under Israeli control for 40 more years.

"Mr. Netanyahu says he needs to stay another 40 years, in any (peace) settlement, in the Jordan Valley," Erekat said. "Of course, he will stay another 400 years with such a profit."

"It's not about security," he said. "It's about stealing land and profiting."

Israeli government spokesman Mark Regev had no immediate comment. Israeli officials have refused to discuss the content of the talks, in line with Kerry's wishes.

Israeli military experts are divided on whether Israel needs to keep the valley on security grounds for a certain period, even after a possible peace deal.

In the past, the Jordan Valley was seen as a buffer against a possible ground invasion from the east, but some say that argument became obsolete in the era of missile warfare and that a peace agreement is a better buffer than a heavy military presence.

However, others say Israel must retain troops in the valley and control the border crossings between the West Bank and Jordan for some time to prevent militants and weapons from entering a future Palestinian state.

For Palestinians, that's a nonstarter. In previous rounds of talks in 2008, they agreed to a demilitarized state and over flights by the Israeli air force and proposed that U.S.-led NATO troops patrol the border, rejecting continued Israeli control in the Jordan Valley.

Since 1967, Israel has severely restricted Palestinian development in the valley which makes about one-fourth of the West Bank. The area remains under full Israeli control and is dotted with Israeli settlements.

Erekat said Palestinians are only permitted to cultivate 4.7 percent of the valley's land.