Donald Trump has gained his first ambassador after lawyer David Friedman was sworn in as the US envoy to Israel.
Vice president Mike Pence administered the oath of office to Mr Friedman, and hailed Mr Trump's decision to nominate his former bankruptcy lawyer for the sensitive diplomatic post as "one of the clearest signs" of the president's commitment to the state of Israel and the Jewish people.
"The president of the United States of America is a lifelong friend of Israel and the Jewish people and, under his leadership, if the world knows nothing else, the world will know this: America stands with Israel," Mr Pence said.
Mr Friedman's wife Tammy, their five children and most of their grandchildren watched the ceremony, along with Ron Dermer, Israel's ambassador to the US.
Mr Friedman, whose nomination faced resistance from Democrats and some Jewish groups, said he was "humbled" by the trust Mr Trump had placed in him.
He also noted his standing as the first of Mr Trump's ambassador nominees to win Senate confirmation and be sworn in to office.
"Those facts speak volumes about how highly the Trump-Pence administration prioritises our unbreakable bond with the state of Israel," he said.
He said he recently resigned from the law firm in which he was a founding partner.
The Senate approved his nomination last week by a vote of 52-46, largely along party lines.
Republican legislators brushed aside complaints from Democrats that the combative lawyer lacked the temperament to represent the US with such a key Middle Eastern ally.
The son of an Orthodox rabbi, he has been a fervent supporter of Israeli settlements, an opponent of Palestinian statehood and a defender of Israel's government.
Mr Friedman tried to use his confirmation hearing before the Senate Foreign Relations Committee in February to repair the damage from his past verbal attacks on individuals who hold opposing views on Israel.
He assured senators that he regretted his choice of language and pledged to be "respectful and measured" if confirmed.
He acknowledged to the committee that he deserved criticism for comments that targeted former president Barack Obama, former secretary of state Hillary Clinton, liberal Jewish advocacy groups and others.
Mr Friedman had called one group, J Street, "worse than kapos" - a reference to Jews who helped the Nazis imprison other Jews during the Holocaust. He also accused Mr Obama of anti-Semitism.
Republicans said his atonement satisfied them, but Democrats argued that his record of divisive statements could not be erased and would compromise his effectiveness as an ambassador.
All 11 Republicans and one Democrat on the committee supported his nomination. The panel's remaining nine Democrats opposed him.