Half of Israelis support annexing parts of the occupied West Bank, although they are divided over whether to take the step without U.S. support, an opinion poll showed on Wednesday.
Some 25 percent of Israelis surveyed by the Israel Democracy Institute think-tank said they want their government to apply sovereignty to Jewish settlements and the Jordan Valley in the West Bank even without backing from Israel's closest ally.
U.S. President Donald Trump's plan for Israeli-Palestinian peace includes Israel keeping most of its settlements in the West Bank, territory that Palestinians seek for a state.
Palestinians have rejected Trump's proposal. They and most countries consider Israel's settlements in the West Bank illegal. Israel disputes this.
Another quarter of the 771 Jewish and Arab Israelis polled preferred annexation only with Washington's backing, while another 30 percent opposed the move entirely. The remaining 20 percent were undecided.
Prime Minister Benjamin Netanyahu has pledged to begin cabinet discussions on July 1 on extending Israeli sovereignty to Jewish settlements and the Jordan Valley - a de facto annexation of land captured in the 1967 Middle East war.
The Trump plan also envisages negotiations leading to a Palestinian state under near-complete Israeli security control, creating what Palestinians leaders say would be an unviable country.
Israeli settler leaders, who met Netanyahu on Tuesday, have voiced concern that annexation under the Trump blueprint would also entail Palestinian statehood and leave some settlements isolated within Palestinian-ruled territory.
Israeli cabinet minister Tzachi Hanegbi said on Army Radio on Wednesday that settlers need not worry "because there will never be" a Palestinian state. Israeli-Palestinian talks collapsed in 2014, part of a now-moribund peace process that began in the 1990s.
This week, Israeli Defence Minister Benny Gantz ordered the military to begin preparing for the consequences of annexation, which could stoke Palestinian unrest.