"They do a lot of things behind the scenes that I wish more people knew about", Haley said, gushing about the couple, "because we are a better country because they're in this administration".
He adds, the U.N.'s differences with the Trump administration "are open and for all to see".
Haley was seen by her counterparts at the United Nations as a voice of clarity in a USA administration that often gave off mixed signals on foreign policy, diplomats say. Menendez said he is concerned about the leadership vacuum she leaves and "the national security impact of her departure at this time of continued disarray for this administration".
She was by no means a card-carrying member of Donald Trump's "America First" nationalism.
Last month Haley wrote an op-ed article in the Washington Post discussing her policy disagreements but also her pride in working for Trump.
Ivanka Trump now serves as a White House advisor with a focus on job creation, economic empowerment, workforce development, and entrepreneurship.
Republican South Carolina Sen.
Nikki Haley resigned today as the U.S. ambassador to the United Nations, in the latest departure from President Donald Trump's national security team.
Interpol president resigns amid Beijing probe
Meng Hongwei, president of Interpol, gives an address at the opening of the Interpol World Congress in Singapore on July 4, 2017. Interpol, consisting of 192 member countries, said on October 7 that it had received Meng's resignation, NBC News reported .
Haley said in her resignation letter to Trump that she would "surely not be a candidate for any office in 2020" and would instead support his re-election bid.
Ms Haley is one of the administration's most popular figures, among Republicans and Democrats, and Mr Trump praised her as a "fantastic person" who has "done an incredible job".
Trump announced, "At the end of the year Nikki will be leaving".
But while Washington insiders questioned whether Haley's departure signaled a new round of palace intrigue, a more prosaic explanation for the move was that she needs to earn a serious private sector salary. Initially, her presence at private meetings between the president and foreign diplomats caused confusion and in some cases outrage, particularly because of concerns about nepotism and because her role has appeared so vague.
Haley also secured three successively tougher Security Council sanction resolutions against North Korea - which the administration has credited with bringing Kim Jong Un to the negotiating table - and an arms embargo against South Sudan.
Haley was appointed to the U.N. post in November 2016 and last month coordinated Trump's second trip to the United Nations, including his first time chairing the Security Council.
The Associated Press wrote this report.
Trump said Haley told him six months ago she wanted to "take a break" by year-end. They spoke on condition of anonymity because they weren't authorized to speak on the record ahead of Trump's announcement. In fact, her political philosophy was far more in tune with what the Republican Party was trying to be after Mitt Romney's disappointing loss to Barack Obama: more open to moderation on immigration, more attractive to African American and Hispanic-American voters, less stiff and condescending on social and fiscal issues.
Haley, formerly the Republican governor of SC, was confirmed as United Nations ambassador in January 2017. She was re-elected in 2014.