President Donald Trump announced on Wednesday that the U.S. will be beginning a process to move its embassy in Israel from Tel Aviv to Jerusalem, and officially recognize the city as Israel's capital.
"I have determined that it is time to officially recognize Jerusalem as the capital of Israel," Trump declared in his statement.
"While previous presidents have made this a major campaign promise, they failed to deliver. Today, I am delivering."
The decision has sparked various reactions from major world leaders, with many concerned that it will hinder peace efforts in the Middle East, though a number of U.S. evangelicals have hailed Trump for keeping his campaign promise.
Here are five important things to know about the controversy behind the decision to recognize Jerusalem as Israel's capital, and the challenges ahead for moving the U.S. embassy.
1. What Makes Jerusalem So Important?
The status of Jerusalem has been up for dispute for centuries, with the Romans, Crusaders, Ottomans and the British Empire among the factions fighting historical battles for control over the city.
Jerusalem contains numerous sacred sites claimed by Christians, Jews, and Muslims, and is where Jesus Christ preached, died, and was later resurrected.
British rule over the area ended in 1948, which led to Jordan's invasion and occupation of the Old City, before Israel captured the land in the 1967 Middle East war. In 1980 Israel declared Jerusalem to be a "complete and united" city and capital of its country, to the protest of Arab countries in the region.
Palestinians, on the other hand, see East Jerusalem as their capital. They live in the city as Israeli residents, receive access to services and vote in municipal elections. Some become Israeli citizens and can vote in parliamentary elections, but most refuse to do so.
The United Nations deems East Jerusalem to be occupied, and has said that the status of the city can only be resolved through negotiations between Israel and Palestine.
2. In 1995 Congress Voted to Move the U.S. Embassy to Jerusalem
While Trump's move has caused significant controversy, U.S. efforts to recognize Jerusalem as Israel's capital have been going on for decades.
Congress passed the Jerusalem Embassy Act of 1995 on October 23, 1995, which allocated funding for relocating the U.S. embassy from Tel Aviv to Jerusalem, at the time aiming to make the transition no later than May 31, 1999.
The bill received overwhelming bi-partisan support, with the Senate passing the legislation by a vote of 93 to 5; while it passed the House 374 to 37, The Washington Post pointed out.
Then-President Bill Clinton refused to sign the bill into law, however, arguing that the act "could hinder the peace process" between Israel and Palestine.
"I will not let this happen and will use the legislation's waiver authority to avoid damage to the peace process," Clinton added at the time.
3. Past Presidents All Recognized Jerusalem as Israel's Capital
Despite Clinton's refusal to sign the Jerusalem Embassy Act into law, he and all the presidents after him have made clear statements during their election campaigns indicating they support recognizing the city as Israel's capital.
Clinton said in February 1992 during the Democratic primaries that he supported recognizing Jerusalem as Israel's capital, Townhall noted. During the general election campaign he argued then-President George H.W. Bush "repeatedly challenged Israel's sovereignty over a united Jerusalem."
George W. Bush in turn attacked Clinton during the 2000 election campaign, criticizing him for failing to deliver on the promise to move the embassy. Bush vowed to "start the process as soon as I'm sworn in," speaking before leading Jewish organizations, including AIPAC and the American Jewish Committee.
Bush never followed through on the promise, however, and instead worked on peace negotiations between Israel and Palestinians, looking to secure a deal on a Palestinian state.
Like his predecessors, Barack Obama also signified that he believes Jerusalem belongs to Israel.
"The Palestinians need a state that is contiguous and cohesive, and that allows them to prosper — but any agreement with the Palestinian people must preserve Israel's identity as a Jewish state, with secure, recognized and defensible borders," Obama declared on June 4, 2008 after capturing the Democratic nomination.
"Jerusalem will remain the capital of Israel, and it must remain undivided. I have no illusions that this will be easy."
Obama, like Bush and Clinton, signed continuous security wavers throughout his presidency delaying the move of the embassy, however.
4. Embassy Move Will Take Years
Finding a location for a U.S. embassy in Jerusalem and completing the move could take a significant amount of time, with the White House suggesting a time frame within three to four years.
Some experts, such as Daniel Shapiro, who served as the U.S. ambassador to Israel under Obama, said that that is a "very optimistic estimate," however.
Shapiro, who is now senior fellow with the Institute for National Security Studies in Tel Aviv, has warned that the embassy move could take five to 10 years, The Washington Post reported.
There is a patch of land in West Jerusalem set aside for a new U.S. embassy, with the lease signed in 1989, but new safety standard rules that came into place following the bombing of U.S. embassies in 1998 means that the designated land is not big enough, Shapiro stated.
5. Threats, Attacks on Israel Could Increase
Arab world leaders have condemned Trump's announcement on Wednesday, with a number warning that it could have grave consequences for peace in the region.
Palestinian militant group Hamas has called for a "day of rage" on Friday, declaring it as the "first day of the intifada against the occupier."
On Thursday, clashes between Palestinian protesters and Israeli soldiers broke out along the West Bank and Gaza Strip, with protesters pelting soldiers with rocks, while Israeli forces fired tear gas and stun grenades.
The Times of Israel reported that defense officials in the country are bracing for "violent protests and terror attacks."
The U.S. embassy in Israel has issued a security warning for U.S. citizens in the country, and has declared that U.S. government employees and their family members are not permitted until further notice to travel to Jerusalem and the West Bank for personal matters.
"United States citizens should avoid areas where crowds have gathered and where there is increased police and/or military presence," the warning stated.