Israel's parliament has passed a Bill stipulating that any plan to cede parts of Jerusalem would require approval by a special majority of 80 Knesset members – two-thirds of the parliament's 120 members.
The law, sponsored by the far-right Jewish Home party, was passed in the early hours of Tuesday by 64-51 votes.
Jerusalem affairs minister Zeev Elkin said after the vote that the amendment strengthened the defensive wall against left-wingers who might try in the future to undermine Israeli sovereignty in "unified" Jerusalem. Jewish Home leader Naftali Bennett said that Jerusalem's unity had been ensured in perpetuity and that there would be no more political manouvres that would enable Jerusalem to be "torn apart".
However, the new law can be overturned by a simple Knesset majority.
The Palestinians seek east Jerusalem as the capital of a future Palestinian state.
Palestinian official Saeb Erekat accused Israel and the United States of attempting to destroy the two-state solution and trying to impose a solution on the Palestinians. He said the Palestinians would resist such moves and will renew their attempt at the United Nations to be accepted as a full member state.
"We don't need new laws on Jerusalem now," Knesset member Nahman Shai of the opposition Zionist Union said. "When Jerusalem burns, everything burns."
Jerusalem has been in the spotlight in recent weeks, after US president Donald Trump ignored multiple warnings and declared that the United States would recognise the city as the capital of Israel. He also announced that he intended to move the US embassy from Tel Aviv to Jerusalem.
In a non-binding resolution, the United Nations General Assembly declared the US move “null and void”.
Violence
Thirteen Palestinians have died in violence since Mr Trump’s announcement – most of them killed in clashes with Israeli forces.
Most countries do not recognise Israel's sovereignty over east Jerusalem, which Israel captured from Jordan during the 1967 Six-Day War. However, Guatemala said it would relocate its embassy to Jerusalem and Israel's deputy foreign minister Tzipi Hotovely said "more than 10 countries" were considering following the American example.
Palestinian president Mahmoud Abbas responded to Mr Trump's declaration by saying the Palestinians would no longer be willing to consider a new American peace initiative, which has still not been unveiled.
Tuesday's Jerusalem law follows the decision on Sunday by the central committee of prime minister Binyamin Netanyahu's ruling Likud party calling for the annexation of West Bank Jewish settlements.
"We are telling the world that it doesn't matter what the nations of the world say," public security minister Gilad Erdan told the gathering. "The time has come to express our biblical right to the land."