President Donald Trump has announced that the US formally recognizes Jerusalem as the capital of Israel and will begin the process of moving its embassy to the city, breaking with decades of US policy.

In a much anticipated speech in Washington on Wednesday, Trump reversed decades of US policy in defiance of warnings from around the world that the gesture risked creating further unrest in the Middle East.

"I have determined that it is time to officially recognize Jerusalem as the capital of Israel," he said.

Trump said he ordered the state department to develop a plan to relocate the American embassy from Tel Aviv to Jerusalem.

He said he was not taking position on any final status issues, including contested borders.

He also said he intended "to do everything" in his power to help forge a peace deal between Israelis and Palestinians.

In his response, Saeb Erekat, the chief Palestinian negotiator, said Trump "destroyed any possibility of peace" and was "pushing this region towards chaos [and] violence".

"He is destroying all moderates in the region and giving power to extremists," Erekat told Al Jazeera.

"This is the most dangerous decision that any US president has ever taken."

Erekat said Trump had "disqualified his country from any possible role in the peace process".

"How can he talk about peace when he dictates the future of Jerusalem before negotiations begin, in total violation of international law?"

Erekat said it is "meaningless" to have a Palestinian state without Jerusalem as its capital.

The only option remaining for Palestinians, he said, "is to fight for equal rights" between the Mediterranean Sea and the Jordan River, the area of historic Palestine.

US analysts say Trump's announcement might be intended as an opening move in the administration's yet-to-be revealed Middle East peace plan, but risks igniting a "powder keg" at the heart of the Israel-Palestine conflict.

"Jerusalem has a tendency to explode when you fool around with the status quo," said Aaron David Miller, vice president at the Woodrow Wilson Center and a former Middle East adviser to the Clinton and Bush administrations.

He said the president's decision could either be part of a strategic plan or a "one-off" born from his desire to fulfil his election campaign promise.

"Some might argue that the president has succeeded at extracting certain assurances from the [Israeli] prime minister on other permanent status issues, but needed this for cover," Miller said.

"I'd love to believe … that there is a coherence here, but if there is, I am at a loss to understand what it is."

The immediate grounds for Trump's announcement was the expiration of the latest six-month waiver delaying relocation of the US embassy from Tel Aviv to Jerusalem.

The 1995 Jerusalem Embassy Act requires the US government to establish an embassy in Jerusalem, but allows the president to delay doing so by signing a waiver every six months. The waiver spares the state department financial penalties for failing to comply with the law.

Presidents Bush and Obama signed the waiver twice per year with little fanfare. However, Trump has long hinted he would deviate from his predecessors.

In the lead-up to Wednesday's speech, Mustafa Barghouti, an independent Palestinian politician, told Al Jazeera: "This is a reckless act from the side of the American president ... . This is a very dangerous act.

"It does not take into consideration what it means to 1.6 billion Muslims, 2.2 billion Christians and 360 million Arabs.

"It will create a very serious reaction and destabilize the region - and definitely destabilize the situation in Palestine itself."

On the campaign trail, candidate Trump promised to move the embassy to Jerusalem and, according to Senator Bob Corker, was ready to do so on day one of his presidency.

When Trump used his waiver power last June, an unnamed White House official was quoted saying the move was "a question of when, not if".

Trump's announcement risks alienating Palestinians and Arab countries that would be key to any peace plan, experts say.

"Accepting to move the embassy to Jerusalem means that the US is participating with Israel in imposing facts on the ground," Barghouti said.

"This is not a single [isolated] act. This US administration that did not speak even once about a two-state solution. This American administration did not say or mention the world Palestinian state once.

"This American administration has failed to exercise any pressure on Israel on the issue of settlements, although Israel has enhanced settlement activities in the occupied territories by no less than 100 percent since President Trump was elected."

For his part, Miller said that by recognising Jerusalem as Israel's capital, Trump is implicitly "validating Israeli claims and sovereignty over part of the city that is aspired to by another national movement".

Brian Katulis, a senior fellow at the Center for American Progress, said the Trump administration has been signalling it will soon debut a plan to resolve one of the world's longest and most intractable conflicts. Wednesday's announcement could be an opening salvo in that plan - an attempt to open discussions.

"If that's what this is, it's likely to backfire given the initial reaction we've seen from some of our closest allies and partners like Jordan," Katulis said.

Public outcry could prime Arab governments to eschew rather than embrace US proposals, he said.

In a statement, John O Brennan, former director of the Central Intelligence Agency, also called Trump's action "reckless", saying it would "damage US interests in the Middle East for years to come and will make the region more volatile".

Message to Palestinians

The announcement is likely to dash hopes that the US would give equal weight to Palestinian concerns in future negotiations - hopes raised when administration officials made an effort to meet Palestinian leaders earlier this year.

"I think this will send a message that US administrations have been sending for years: that the Palestinians are not as important as the Israelis, or their views are not as important," said Katulis.

Jerusalem has long been a flashpoint in Israeli-Palestinian relations. Violence broke out most recently last summer, after Israeli authorities installed metal detectors at entrances to the al-Aqsa compound.

"I can't predict violence - I don't know," said Miller. "But certainly, if you wanted to make an issue out of this, a quote-unquote 'defense of Jerusalem,' it's a ready-made issue."

World leaders have warned violent reactions to the US embassy announcement are a distinct possibility.

King Abdullah II of Jordan - speaking at a press conference in Istanbul with Turkish President Recep Tayyip Erdogan on Wednesday - said the US was inviting blowback with the decision.

"Ignoring the Palestinian, Muslim, and Christian rights in Jerusalem will only fuel further extremism and undermine the war against terrorism," Abdullah said.

Erdogan also highlighted the threat of violence after the US decision.

"No one has the right to play with the fate and development of millions of people for the sake of personal ambitions. Such a step will only play into the hands of terror groups," Turkey's president said.

But analysts said the embassy decision will please religious conservatives among Trump's base, as well as major donors.

Rabbi Alissa Wise, deputy director of the left-wing advocacy group Jewish Voice for Peace, said US evangelical Christians - who voted overwhelmingly for Trump in the 2016 election - are staunch supporters of Israel's right-wing government. Wise also cited billionaire Sheldon Adelson, one of Trump's largest campaign donors, as a possible source of pressure on the president to back Israel's claim to a united Jerusalem.

Wise is worried the decision would frame a political struggle over land, rights and sovereignty in religious terms.

"Because Jerusalem is a symbol of holiness to so many religions, creating a tension around Jerusalem runs the risk of shaping or framing this conflict as a religious one, which I think gets us further and further away from a more equitable solution," Wise said.

"It really is a match in the powder keg, a decision like this."

For his part, Barghouti, the Palestinian politician, said: "This is an administration that obviously is, to a large extent, taking its decision according to the will and pressure of the Israeli Zionist lobby in Washington.

"The Palestinian people will react, with a public, popular non-violent uprising. That's what you will see tomorrow, after tomorrow and the days after.

"This is a very serious matter. People should not forget that the second intifada started because of the issue of Jerusalem and I believe that ... Trump will be killing completely any future American role in any future peace process."

PHOTO CAPTION

With Vice Pence Mike Pence looking on, U.S. President Donald Trump signs an executive order after he announced the U.S. would Jerusalem as the capital of Israel, in the Diplomatic Reception Room of the White House in Washington, U.S., December 6, 2017. REUTERS/Kevin Lamarque

Al-Jazeera