TOPSHOT - A Palestinian youth waves the national flag as Israeli military digs in search of smuggling tunnels at the border east of Gaza city on May 15, 2016, on the 68th anniversary of the "Nakba".
"Nakba" means in Arabic "catastrophe" in reference to the birth of the state of Israel 68-years-ago in British-mandate Palestine, which led to the displacement of hundreds of thousands of Palestinians who either fled or were driven out of their homes during the 1948 war over Israel's creation.
 / AFP / MAHMUD HAMS        (Photo credit should read MAHMUD HAMS/AFP/Getty Images)
MAHMUD HAMS/AFP/AFP/Getty Images
TOPSHOT - A Palestinian youth waves the national flag as Israeli military digs in search of smuggling tunnels at the border east of Gaza city on May 15, 2016, on the 68th anniversary of the "Nakba". "Nakba" means in Arabic "catastrophe" in reference to the birth of the state of Israel 68-years-ago in British-mandate Palestine, which led to the displacement of hundreds of thousands of Palestinians who either fled or were driven out of their homes during the 1948 war over Israel's creation. / AFP / MAHMUD HAMS (Photo credit should read MAHMUD HAMS/AFP/Getty Images)
Now playing
00:50
Arab leaders condemn Trump's Jerusalem plan
israel prime minister benjamin netanyahu iran deal reaction sot _00002125.jpg
israel prime minister benjamin netanyahu iran deal reaction sot _00002125.jpg
Now playing
01:55
Netanyahu: Israel thanks Trump for his courage
United States Ambassador to the United Nations, Nikki Haley, addresses the General Assembly prior to the vote on Jerusalem, on December 21, 2017, at UN Headquarters in New York.
UN member-states were poised to vote on a motion rejecting US recognition of Jerusalem as Israel's capital, after President Donald Trump threatened to cut funding to countries that back the measure.  / AFP PHOTO / EDUARDO MUNOZ ALVAREZ        (Photo credit should read EDUARDO MUNOZ ALVAREZ/AFP/Getty Images)
EDUARDO MUNOZ ALVAREZ/AFP/AFP/Getty Images
United States Ambassador to the United Nations, Nikki Haley, addresses the General Assembly prior to the vote on Jerusalem, on December 21, 2017, at UN Headquarters in New York. UN member-states were poised to vote on a motion rejecting US recognition of Jerusalem as Israel's capital, after President Donald Trump threatened to cut funding to countries that back the measure. / AFP PHOTO / EDUARDO MUNOZ ALVAREZ (Photo credit should read EDUARDO MUNOZ ALVAREZ/AFP/Getty Images)
Now playing
01:14
Haley threatens to pull US funding to the UN
WASHINGTON, DC - DECEMBER 06:  US President Donald Trump announces that the U.S. government will formally recognize Jerusalem as the capital of Israel as Vice President Mike Pence looks on in the Diplomatic Reception Room at the White House December 6, 2017 in Washington, DC. In keeping with a campaign promise, Trump said the United States will move its embassy from Tel Aviv to Jerusalem sometime in the next few years. No other country has its embassy in Jerusalem.  (Photo by Chip Somodevilla/Getty Images)
Chip Somodevilla/Getty Images North America/Getty Images
WASHINGTON, DC - DECEMBER 06: US President Donald Trump announces that the U.S. government will formally recognize Jerusalem as the capital of Israel as Vice President Mike Pence looks on in the Diplomatic Reception Room at the White House December 6, 2017 in Washington, DC. In keeping with a campaign promise, Trump said the United States will move its embassy from Tel Aviv to Jerusalem sometime in the next few years. No other country has its embassy in Jerusalem. (Photo by Chip Somodevilla/Getty Images)
Now playing
01:54
Trump's words on Jerusalem over the years
israel trump naming frenzy liebermann pkg_00012022.jpg
israel trump naming frenzy liebermann pkg_00012022.jpg
Now playing
02:09
Israel sees Donald Trump naming frenzy
Jerusalem's Temple Mount
CNN
Jerusalem's Temple Mount
Now playing
01:59
Why Jerusalem's holy sites are so significant
CNN
Now playing
01:05
Protests erupt over Trump's Jerusalem decision
The results of the vote on Jerusalem are seen on a display board at the General Assembly hall, on December 21, 2017, at UN Headquarters in New York.
UN member-states were poised to vote on a motion rejecting US recognition of Jerusalem as Israel's capital, after President Donald Trump threatened to cut funding to countries that back the measure.  / AFP PHOTO / EDUARDO MUNOZ ALVAREZ        (Photo credit should read EDUARDO MUNOZ ALVAREZ/AFP/Getty Images)
EDUARDO MUNOZ ALVAREZ/AFP/AFP/Getty Images
The results of the vote on Jerusalem are seen on a display board at the General Assembly hall, on December 21, 2017, at UN Headquarters in New York. UN member-states were poised to vote on a motion rejecting US recognition of Jerusalem as Israel's capital, after President Donald Trump threatened to cut funding to countries that back the measure. / AFP PHOTO / EDUARDO MUNOZ ALVAREZ (Photo credit should read EDUARDO MUNOZ ALVAREZ/AFP/Getty Images)
Now playing
01:39
UN votes to condemn Trump's Jerusalem decision
US President Donald Trump delivers a statement on Jerusalem from the Diplomatic Reception Room of the White House in Washington, DC on December 6, 2017.
MANDEL NGAN/AFP/Getty Images
US President Donald Trump delivers a statement on Jerusalem from the Diplomatic Reception Room of the White House in Washington, DC on December 6, 2017.
Now playing
00:56
Trump recognizes Jerusalem as Israeli capital
CNN
Now playing
01:18
Haley on Jerusalem: This is about courage
CNN
Now playing
01:52
Columnist: Trump gave away the crown jewel
jerusalem world away wedeman pkg_00015028.jpg
jerusalem world away wedeman pkg_00015028.jpg
Now playing
02:26
Palestinian refugees indifferent to Trump's plan
US President Donald Trump delivers a statement on Jerusalem from the Diplomatic Reception Room of the White House in Washington, DC on December 6, 2017 as US Vice President Mike Pence looks on.
SAUL LOEB/AFP/Getty Images
US President Donald Trump delivers a statement on Jerusalem from the Diplomatic Reception Room of the White House in Washington, DC on December 6, 2017 as US Vice President Mike Pence looks on.
Now playing
01:18
Trump: US will support a 2-state solution
jerusalem tillerson mideast peace sot_00000000.jpg
jerusalem tillerson mideast peace sot_00000000.jpg
Now playing
00:46
Tillerson: Good opportunity for peace
CNN
Now playing
01:43
Jerusalem mayor: I applaud Donald Trump
Jewish people take part in the Cohanim prayer (priest's blessing) during the Passover (Pesach) holiday at the Western Wall in the Old City of Jerusalem on April 13, 2017, with the Dome of the Rock seen in the background.
THOMAS COEX/AFP/AFP/Getty Images
Jewish people take part in the Cohanim prayer (priest's blessing) during the Passover (Pesach) holiday at the Western Wall in the Old City of Jerusalem on April 13, 2017, with the Dome of the Rock seen in the background.
Now playing
01:25
Confusion over status of Western Wall
(CNN) —  

US President Donald Trump’s pledge to declare Jerusalem as the capital of Israel has caused controversy across the world.

Trump could announce the move as early as Tuesday, US officials with direct knowledge of the matter and foreign diplomats have told CNN.

Upon making his decision public, Trump is expected to sign a waiver to keep the US embassy in Tel Aviv for another six months, but say his administration will move the diplomatic mission to Jerusalem at some point – a goal long sought by Israel.

Trump told CNN in March that moving the embassy would happen “very quickly.”

The State Department’s security arm has been told to plan for potentially violent protests at US embassies and consulates if the Trump administration announces it is moving the embassy in Israel to Jerusalem.

CNN’s Oren Liebermann, who is based in Jerusalem, walks us through what’s at stake.

So why is moving the embassy such a big deal?

If the United States moved the embassy to Jerusalem, it would mean that the US effectively recognizes Jerusalem as the capital of Israel. That would overturn 70 years of international consensus, and, many argue, would effectively signal the end of moves to achieve peace between Israelis and Palestinians.

Give me some history…

The United Nations partition plan drawn up in 1947 envisaged Jerusalem as a separate “international city.” But the war that followed Israel’s declaration of independence one year later left the city divided. When fighting ended in 1949, the armistice border – often called the Green Line because it was drawn in green ink – saw Israel in control of the western half, and Jordan in control of the eastern half, which included the famous Old City.

When did that change?

During the 1967 Six-Day War, Israel occupied East Jerusalem. Since then, all of the city has been under Israel’s authority. The city marks “Jerusalem Day” in late-May or early-June. But Palestinians, and many in the international community, continue to see East Jerusalem as the capital of a future Palestinian state.

Have any countries ever had their embassy in Jerusalem?

Yes. Before 1980 a number of countries did, including the Netherlands and Costa Rica.

Right. So what happened?

In July of 1980, Israel passed a law that declared Jerusalem the united capital of Israel. The United Nations Security Council responded with a resolution condemning Israel’s annexation of East Jerusalem and declared it a violation of international law.

So countries moved their embassies out of the city?

Correct. In 2006, Costa Rica and El Salvador were the last to move their embassies out of Jerusalem, joining the rest of the world in locating their embassies in Tel Aviv.

What about consulates?

Some countries do maintain consulates in Jerusalem, including the United States, which has one in the western part of the city. Other countries – such as Britain and France for instance – have a consulate in the eastern part of the city, which serve as their countries’ main representation in the Palestinian territories.

Just to be clear: What is America’s position?

The US has never had its embassy in Jerusalem. It has always been in Tel Aviv, with the Ambassador’s residence in Herzliya Pituach, about 30 minutes north.

00:08 - Source: CNN
Trump on moving the US Embassy

That sounds pretty straightforward…

Wait a minute, it gets more complicated. In 1989, Israel began leasing to the US a plot of land in Jerusalem for a new embassy. The 99-year lease cost $1 per year. To this day, the plot has not been developed, and it remains an empty field.

OK. Keep going…

In 1995, the US Congress passed a law requiring America to move the embassy from Tel Aviv to Jerusalem. Proponents said the US should respect Israel’s choice of Jerusalem as its capital, and recognize it as such.

So why hasn’t the embassy moved yet?

Every president since 1995 – Presidents Clinton, Bush and Obama – has declined to move the embassy, citing national security interests. Every six months, the President has used the presidential waiver to circumvent the embassy move.

03:39 - Source: CNN
Israel amb. supports U.S. Embassy Jerusalem move

What are Trump’s options if he goes ahead with the embassy move?

The first is to make use of the undeveloped plot that the US has been leasing since 1989. Or the US could turn its existing consulate in Jerusalem into the embassy. A final option might be to leave the embassy in Tel Aviv, but have the US Ambassador to Israel do his day-to-day work in Jerusalem.

MORE: Trump pushes US embassy move in Israel amid outcry

How have Israelis responded to this?

The Israeli government has lauded Trump’s pledge to follow through with the embassy move. Jerusalem Mayor Nir Barkat has been perhaps the most outspoken advocate, launching a campaign just days before the US President’s inauguration, urging him to make good on his promise.

And what do the Palestinians make of it all?

Palestinian leaders are adamant that an embassy move to Jerusalem would be a violation of international law, and a huge setback to peace hopes.

President Mahmoud Abbas has turned to other world leaders, including Russian President Vladimir Putin and Jordan’s King Abdullah, to help pressure Trump to change his mind. The Palestine Liberation Organization has suggested it would consider revoking its recognition of Israel, and canceling all agreements between Israelis and Palestinians, should the move take place.

More immediately, there are fears it could set off a wave of unrest – perhaps even street protests and violence – in the Palestinian territories and across the Arab world.

The powerful Iraqi Shiite cleric, Muqtada al-Sadr, warned in January a statement on his website that moving the US embassy to Jerusalem would represent a declaration of open war against Islam. He called for the closure of the Israeli and US embassies in Islamic countries.

CNN’s Caroline Kenny contributed to this article.