U.N. Ambassador Nikki Haley is among a select few Cabinet aides who speak frequently and directly with the president. (Jabin Botsford/The Washington Post)

U.N. Ambassador Nikki Haley quickly became one of the administration’s most visible faces and the leading advocate for a worldview in which President Trump’s “America First” slogan did not mean “America alone.”

When Trump makes his second presidential appearance at the United Nations this week, Haley will still be a central figure, and their close rapport is likely to be apparent. She is among a select few Cabinet aides who speak frequently and directly with the president, a sore spot for some White House officials.

But Haley’s public role has ­narrowed as Trump’s national ­security Cabinet was shuffled over the past year and advisers who advanced more nationalist agendas on trade, immigration and international engagement gained favor.

A pair of incidents in which Haley announced policies or plans that were quickly changed also raised questions about her footing in the administration as Secretary of State Mike Pompeo and national security adviser John Bolton took over from more passive and ideologically moderate aides. In both cases, several senior officials said she was unfairly scapegoated.

At the same time, Haley’s influence at the United Nations has been blunted by Trump policy decisions that many other nations opposed, including recognizing Jerusalem as the Israeli capital, cutting aid to Palestinians and announcing a U.S. withdrawal from the U.N. Human Rights Council.

Haley supports those positions, along with Trump’s theme that American largesse will not be wasted on those who are undeserving or ungrateful. But she has lost on other policy debates, including a further reduction in the number of refugees who can be resettled in the United States, which was announced last week.

“The goal that we all have as an administration is, how we can make the American people proud, and what actions we can show that really live up to that,” Haley said as she previewed Trump’s U.N. visit, which begins Monday.

Trump’s address Tuesday is ­focused on American sovereignty and foreign aid, aides said. His adviser Stephen Miller, who is con­sidered the architect of the administration’s strictest immigration policies and a sometime opponent of Haley’s, is a principal author of the president’s U.N. speech.

“He’ll also lay down a marker that while the United States is generous, we’re going to be generous to those that share our values, generous to those who want to work with us, and not those that try to stop the United States or say they hate America,” Haley said at a news conference Thursday at the United Nations.

By chance, the United States holds the rotating chairmanship of the U.N. Security Council this month, meaning Haley can call sessions on themes of special interest. She has used the platform to hold debates about crumbling democracy in Venezuela, the political crisis in Nicaragua and North Korea’s evasion of U.N. sanctions, all topics in line with administration priorities.

The chairmanship also means that Trump and Pompeo can each take a turn with the gavel during the annual U.N. gathering.

Pompeo, a Trump favorite, is making his debut at the U.N. General Assembly with an agenda focused on North Korea. Pompeo will chair a Security Council session where he is to lay out Trump’s hopes for a peaceful dismantlement of North Korea’s nuclear weapons and warn countries that bust U.N. sanctions on the country.

Haley was a more prominent player on North Korea during the first year of the Trump administration, when the focus was on rallying international support for tougher international sanctions and Rex Tillerson was secretary of state. She has been less visible through the swift turn to summit diplomacy this year, where Pompeo has been the negotiator. She did not attend Trump’s ­historic summit with North Korean leader Kim Jong Un in Singapore in June, but only because there is no role for the U.N. ambassador at such an event, according to several administration officials, who spoke on the condition of anonymity to discuss internal decision-making.

Bolton has shaken up the staff at the National Security Council and cut back on the kind of high-level meetings Haley regularly attends. Former U.S. officials say Bolton will be tempted to dictate how Haley does her job given his granular and deeply critical understanding of the world body stemming from his time as a U.N. ambassador.

“Haley’s influence was at its peak in the Rex Tillerson era, since his withdrawn nature allowed her to take the stage and be the voice of U.S. foreign policy,” said Molly Montgomery, a career U.S. diplomat who worked in Vice President Pence’s office before leaving government earlier this year. “Naturally, she’s less prominent now because Pompeo is so much more engaged with foreign governments and the press.”

On esoteric issues involving the United Nations, such as peacekeeping missions in Africa, Haley was given broad autonomy by former national security adviser H.R. McMaster, who had little interest in micromanaging U.S. policy at the United Nations.

“Now Bolton has exerted himself more on U.N. matters than his predecessor, given his interest in the body and his own experience in New York during the George W. Bush administration,” Montgomery said.

White House officials say Bolton and Haley’s relationship is strong, and his interest in the United Nations hasn’t come at Haley’s expense. But longtime aides of Bolton say tensions between the two are inevitable.

“Bolton has a very aggressive approach to the U.N. and inside the U.S. government is very practiced at pulling bureaucratic strings and operating in front of cameras and behind the scenes,” said Matthew Waxman, a former George W. Bush administration official.

“Bolton runs an imperial NSC,” added Mark Groombridge, a former adviser to Bolton at the State Department and United Nations. “Of course he’s going to want to exert influence over Ambassador Haley.”

National Security Council spokesman Garrett Marquis said Bolton is “successfully coordinating across government to implement the president’s agenda.”

Before he took the White House job, Bolton was a critic of a decision by Democratic presidents Bill Clinton and Barack Obama to make the U.N. job a Cabinet-level position. He argued that it inflated the importance of the United Nations in U.S. decision-making and created an untenable power structure with two Cabinet secretaries in one department.

Haley insisted on Cabinet rank to take the job, and Trump agreed. Bolton has never made it an issue, one senior administration official said.

“He has in no way treated her as less than a full Cabinet member,” the official said. “In some ways she thinks Bolton’s approach is preferable. There were probably too many meetings previously, and it functions better now.”

Bolton, like Pompeo, has Trump’s confidence in ways his predecessors did not. That generally makes the process of determining and overseeing national security policy smoother, several officials said, but it does not prevent events one described as “miscommunication” and another as a “goof.”

One awkward incident came this month when Haley said the president would chair a Security Council session on Iran, but other U.S. officials later said the agenda would be broadened to nonproliferation. The change followed an internal debate about whether the Iran focus would provoke a public rift with allies Britain and France over the Iran nuclear deal Trump disavowed this year, and invite trouble by placing Trump and an Iranian representative at the same table.

Haley formally announced the switch Thursday and called it sensible, but by then several days had passed when it was unclear whether she had gotten ahead of the White House or was behind and out of the loop.

It was Trump who had wanted to focus on Iran, said two U.S. officials who spoke on the condition of anonymity to offer a ­behind-the-scenes view. Trump tweeted Friday that he would chair a session “on Iran,” and a senior administration official said that should be interpreted as confirmation that the president still prefers that focus.

“The Iran topic was discussed thoroughly throughout the national security team before it was announced. After it was announced, there was a reconsideration about whether that was the best course,” the official said. “She was part of that reconsideration, just as she was part of the initial discussion of the topic. She agreed to the expansion of the topic and thought the new approach was the better way to go.”

Exactly how the Trump administration plans to engage with Iran remains unclear. On Sunday, Pompeo said there were no plans for a meeting between Trump and Iran’s president, Hassan Rouhani, in New York this week — but coyly suggested a tete-a-tete with the country’s supreme leader, Ayatollah Khamenei, could be “an important and interesting conversation.”

The decision to change the focus of the Security Council meeting had echoes of another miscommunication, in April, about a week after Bolton took over. Haley announced on television new sanctions on Russia that Trump vetoed hours later. The White House did little to dispel the perception that Haley had misspoken, and one White House official publicly said she had suffered “momentary confusion.” But Haley shot back in a defiant statement saying, “With all due respect, I don't get confused,” and the White House backed off.

“The idea that she would freelance is absurd at every possible level,” the senior official said. “She operates within the team structure every day. The best proof of that is the dozens of engagements she has at the U.N. that go off flawlessly.”

Despite the early hiccup, Marquis insisted that NSC staff and Haley’s office are “working hand-in-glove” to prepare for the U.N. General Assembly this week, and State Department spokeswoman Heather Nauert said Bolton, Haley and Pompeo work together “seamlessly.”

The friction between the camera-ready Haley and the secretive, media-shy Tillerson was obvious, and their two staffs often tussled over policy matters.

Haley was widely seen to be filling the public void left by Tillerson, fueling speculation she was auditioning for the higher post. She denied it emphatically, telling reporters at last year’s U.N. General Assembly that she had no designs on Tillerson’s job.

Not long afterward, Tillerson lost an internal debate when Trump announced Dec. 6 that the U.S. Embassy in Israel would be moved from Tel Aviv to the contested city of Jerusalem. The decision outraged Palestinians, who said it prejudged their claim to East Jerusalem, and opened a diplomatic gulf at the United Nations.

A lopsided 128-to-9 U.N. vote to criticize the U.S. move included 35 abstentions, which Haley and the White House framed as a victory. The largely symbolic vote followed a warning from Haley about U.S. funding for the world body.

“When we make generous contributions to the U.N., we also have a legitimate expectation that our goodwill is recognized and respected,” she said. “When a nation is singled out for an attack in this organization, that nation is disrespected. What’s more, that nation is asked to pay for the privilege of being disrespected.”

A former Haley staffer said the U.N. ambassador expected a difficult vote at the Security Council, but “did not anticipate” a vote at the U.N. General Assembly. The official spoke on the condition of anonymity to avoid antagonizing the ambassador. The ensuing vote saw many key U.S. allies side against the United States, including Britain, France, Germany and Japan, in a rare rebuke of U.S. policy.

Regardless of the vote outcome, Haley's unapologetic defense of Israel cemented her support among a pro-Israel donor class that could prove useful if she pursues higher political office.

“She scored points with the people she wanted to score points with, especially the AIPAC crowd,” the former official said, referring to the American Israel Public Affairs Committee, the most powerful pro-Israel lobbying organization.

Though Haley could walk away from the Trump administration at any time claiming experience with some of the weightiest foreign policy issues of the day, she appears less prone to an early exit than others, said a senior administration official who has dealt with Haley and her staff from the beginning.

“I do get the rumors of who’s on the up and who’s on the down, and Nikki’s name just hasn’t come up lately,” the official said.