A group of Israeli cabinet ministers has endorsed a legislative proposal to annex a part of the occupied West Bank that would serve as the eastern border of a future Palestinian state, putting pressure on floundering US-brokered peace negotiations.

The move to annex the Jordan Valley, which makes up almost 30 percent of the occupied West Bank, was approved by members of Israeli Prime Minister Benjamin Netanyahu's Likud party in the cabinet's legislative committee on Sunday.

The move came just days before another visit to the region by US Secretary of State John Kerry, who is pushing for a peace agreement between Israelis and Palestinians.

Justice Minister Tzipi Livni, who is leading Israel's side in the negotiations, immediately challenged the motion.

She said she would use her powers to block the legislation from being voted on in Israel's parliament, the Knesset.

Earlier this month, Kerry said in Washington that the need to resolve the dispute over the Jordan Valley was "a critical threading of a needle that has to happen in order to achieve an agreement".

He said he was coordinating with Jordan on the issue, as well.

'Palestinian breadbasket'

Israel took control of the Jordan Valley region following the 1967 war. Known as the "Palestinian breadbasket", the Jordan Valley contains most of the West Bank's fertile, agricultural lands.

Israel says maintaining control over the Jordan Valley is crucial to its security interests.

A Palestinian source said a security proposal presented by Kerry earlier this month as part of the peace talks outlined leaving an Israeli military presence in the Jordan Valley for at least 10 years, Reuters news agency reported.

Palestinians rejected the Israeli demand, and the Arab League said the proposal "achieved Israeli security expansionist demands, and guaranteed [Israel's] continued control of [the Jordan Valley] on the security pretext".

Israel's proposal to incorporate the Jordan Valley within its borders is the first Israeli step in decades to annex any territory it captured in 1967.

Shortly after that war, in a move that remains unrecognised internationally, Israel annexed East Jerusalem and added some adjoining Palestinian land from the occupied West Bank to the city, which it regards as its "eternal, undivided" capital.

In 1981, Israel also applied its laws to the occupied Syrian Golan Heights, a strategic plateau that lies to the north.