UN Secretary-General Antonio Guterres on Saturday defended his choice of former Palestinian prime minister Salam Fayyad to be the UN peace envoy to Libya after the United States blocked the appointment.
The decision to put forward his candidacy "was solely based on Mr Fayyad's recognized personal qualities and his competence for that position," said UN spokesman Stephane Dujarric.
"United Nations staff serve strictly in their personal capacity. They do not represent any government or country," he said.
Guterres had informed the Security Council earlier this week of his intention to appoint Fayyad and set a deadline of Friday for members to raise objections.
Diplomats had said they expected the appointment to be approved, but US Ambassador Nikki Haley decided to oppose it.
Haley said in a statement that the United States did not "support the signal this appointment would send within the United Nations," where the state of Palestine does not have full membership.
"For too long the UN has been unfairly biased in favor of the Palestinian Authority to the detriment of our allies in Israel," she said in a statement.
Dujarric said no Israeli and no Palestinian had served in a high-level post at the United Nations and that "this is a situation that the secretary-general feels should be corrected," based on personal merit and competencies of the candidates.
Appointments of the UN special representatives of the secretary-general require the unanimous backing of the 15-member council.
Fayyad, 64, was prime minister of the Palestinian Authority from 2007 to 2013, and also served as finance minister twice.
He had been tapped to replace Martin Kobler of Germany, who has been the Libya envoy since November 2015.
Palestine Liberation Organisation executive committee member Hanan Ashrawi condemned the US decision as "blatant discrimination."
US President Donald Trump and Haley have criticized the United Nations for adopting a resolution in December that demanded an end to Israeli settlement building.
"Going forward, the United States will act, not just talk, in support of our allies," Haley said.