The Palestinian president, Mahmoud Abbas, has warned Israel and the US not to cross “red lines” as anxiety mounts over the impending release of Donald Trump’s peace plan proposal, which is widely expected to be tilted heavily in Israel’s favour.

A spokesman for Abbas said the Palestinian leadership had a “clear and unwavering position” to reject any Trump-led initiatives.

In a separate statement, and referring to reports that the plan might allow Israel to permanently control Palestinian territory the spokesman, Nabil Abu Rudeinah, said: “We warn Israel and the American administration against crossing the red lines.”

Trump has said he will probably release details of his long-delayed plan for the Middle East before next Tuesday, after he invited the Israeli prime minister, Benjamin Netanyahu, and the leader of the opposition, Benny Gantz, to Washington for talks.

Speaking onboard Air Force One en route to Miami on Thursday, the US president compared solving one of the world’s most intractable territorial disputes to a business deal.

“I love doing deals,” he told reporters.

“They say peace between Israel and the Palestinians is the toughest – the toughest of any deal.” He added he would “probably release” the plan a little prior to the Tuesday meeting.

Few political aspects of the proposal, which has been drafted by Trump’s son-in-law, Jared Kushner, have been released. Kushner proposed a $50bn economic plan in July to a cool regional reception. Palestinian leaders have long rejected any Trump-led peace initiatives as biased, and an attempt to bully them to relinquish long-held demands for a state and a resolution for Palestinian refugees.

Trump said he had spoken “briefly” to Palestinian leaders. “I’m sure they maybe will act negatively at first, but it’s actually very positive for them. But they have a lot of incentive to do it,” he said. The Palestinian president’s office denied they had spoken to Trump.

The Guardian understands that unlike previous attempts that have focused on getting Israeli and Palestinians leaders to find common ground, Washington’s new plan is drafted to be a prescriptive, take it or leave it, proposal.

Israeli media, citing unnamed Israeli officials, reported that the measures would be extremely favourable to the country, allowing it to annex much of the Palestinian territories, including Jewish settlements, and all of contested Jerusalem. The Palestinians may be granted some form of self-rule but under tight restrictions.

Those points, unconfirmed by the Guardian, would be in line with US foreign policy in the region under the Trump administration, which has promoted itself as the most pro-Israel in US history.

Washington reversed decades of its own policy by refraining from endorsing a two-state solution. It has also recognised Jerusalem as Israel’s capital, cut millions of dollars in aid to Palestinians, and announced that it no longer views Israeli settlements in occupied territory as “inconsistent with international law”.

Salem Barameh, executive director of the Ramallah-based Palestine Institute for Public Diplomacy, said the plan was “political theatre” and that Trump and his team had already implemented their vision for an expanded, dominant Israel. Trump’s ambassador to Israel, his company’s former bankruptcy lawyer, David Friedman, has been a longtime supporter of the Israeli settlement movement.

“Whether it’s the Trump administration or the ruling Israeli government, they have the same ideology,” Barameh said. Trump was releasing his plan now, he said, so that the Palestinians would be forced to reject it and be portrayed as uncompromising. That would give Washington a pretext to support Israeli plans to annex Palestinian land.

“I don’t see how anything can be offered that any Palestinian leader can accept. There is only one reaction that can come from the Palestinian side, and that is rejection.”

Saeb Erekat, the secretary general of the Palestine Liberation Organisation, said any proposal that ignored Palestinian rights would be “recorded in history as the fraud of the century”. The unreleased plan has been referred to as the “deal of the century”.

The US had tried to release the plan before, but Israel has been engulfed in a political crisis after two inconclusive elections. They have left uncertainty over who will be in charge to negotiate such a deal. A third election is planned for 2 March and, by inviting both leading candidates, Washington hopes to get Israel’s next leader onboard in advance.

Israeli political analysts interpreted the timing, however, as beneficial for Netanyahu, Trump’s rightwing ally, as it would distract from three ongoing corruption cases. Netanyahu argues that only he has the ability to get world leaders to agree to Israel’s demands.

The commentator Nahum Barnea, writing in the country’s top-selling Yedioth Ahronoth newspaper, said: “For better or for worse, the announcement of the deal – both its timing and its political ramifications – is a huge achievement for Netanyahu. Time will tell whether it is his lifeline or his swan song.”

Another piece in the same newspaper by Ben-Dror Yemini called on Israel to implement the agreement. It said: “Israeli governments in the past agreed to much less generous plans. So obviously we can and must agree to a plan that offers the Palestinians much less.”