Friedman has backed arch-conservative Jewish settlements in some occupied Palestinian territories
David Friedman, a Jewish American attorney close to President Donald Trump, who is known for a hardline stand in favour of settlements in occupied territories, was sworn in on Wednesday as new US envoy to Israel.
The Senate confirmed his nomination in a 52-46 vote.
"One of the clearest signs of the president's commitment to the state of Israel and to its people is in his choice of David Friedman as America's Ambassador to Israel," Vice President Mike Pence said at the event.
A longtime attorney and the son of a rabbi, Friedman has backed arch-conservative Jewish settlements in some occupied Palestinian territories, as well as moving the US embassy to Jerusalem from Tel Aviv.
"This is a critical time for our two nations and our peoples. The challenges we face are many, but our resolve to overcome them has never been stronger," Pence said.
"Under President Trump's leadership, the United States will always be a faithful friend to the Jewish State of Israel."
— Eric Cortellessa (@EricCortellessa) March 23, 2017
The Israel job was seen as a key bellwether of the new administration's attitude to the Israeli-Palestinian conflict, and Friedman's nomination was welcomed by the Israeli right.
Israeli Prime Minister Benjamin Netanyahu declared on Twitter that Friedman "will be warmly welcomed as President Trump's representative and as a close friend of Israel".
Before becoming the ambassadorial nominee, Friedman was known as a vocal supporter of Israeli causes, including the building of settlements on Palestinian land in Jerusalem and the West Bank.
He clashed with American Jewish progressive groups, notably dubbing liberals "worse than kapos," a reference to Jewish collaborators who worked as guards in Nazi prison camps.
And he is widely seen as hostile to the two-state solution - the vision of an end to the conflict in which Israel and a future Palestine live side-by-side within agreed borders.
Senate confirms bankruptcy lawyer David Friedman as Ambassador to Israel. Crowded diplomatic area: Greenblatt, Kushner, etc.
— Olivier Knox (@OKnox) March 23, 2017
Trump's administration insists it might support this idea if Israel and Palestine reach a deal, but has clearly softened the Obama administration's tough criticism of Israeli settlements.
Democratic senator Dianne Feinstein voted against Friedman and dubbed him "too divisive to serve in one of our nation's most sensitive diplomatic positions".
And liberal Jewish lobby group J Street said it was "heartened" that the level of opposition to Friedman's confirmation showed that his views were outside the US mainstream.
Meanwhile, Pence on Sunday revived talk of the possibility the US may move its embassy to Jerusalem from Tel Aviv, saying Trump was seriously considering the matter.
During the 2016 US presidential campaign, Trump's team spoke often about moving the embassy to Jerusalem. But since taking office, the contentious issue appears to have moved to the backburner.
"After decades of simply talking about it, the president of the United States is giving serious consideration to moving the American embassy from Tel Aviv to Jerusalem," Pence said in a recent speech to the influential, pro-Israel US lobbying group AIPAC.