Stephen Miller, a senior adviser to President Donald Trump, has been the architect behind the administration's immigration policy.

A lengthy New Yorker profile detailed how during one heated exchange last year, Miller said he didn't have a "family" and immigration policy was the only thing that mattered to him.

At the time, he was dating Mike Pence's press secretary Katie Waldman, who he married on Sunday.

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When things became heated at a meeting about immigration policy last year, Stephen Miller, senior adviser to President Donald Trump, said the discussion at the time — about limiting asylum in the United States — was the only thing that mattered to him.

"I didn't mean to come across as harsh," Miller, 34, said, according to a report from The New Yorker. "It's just that this is all I care about. I don't have a family. I don't have anything else. This is my life."

At the time, he was dating and reportedly engaged to Mike Pence's press secretary Katie Waldman. They got married on Sunday.

The lengthy profile from The New Yorker, published on Friday, details the nature of the president's longest-serving senior aide, who has monopolized White House's immigration policy efforts and has become the architect behind some of Trump's most controversial actions, including the "zero tolerance" policy that separated migrant children from their parents.

His comments were made at a meeting he organized last November, which included officials from the Departments of Homeland Security, State, and Justice, sources told The New Yorker. The purpose of the meeting was to discuss a new administration policy to limit asylum seekers from settling in the US.

The plan relied on crafting agreements with Central American nations in order to force asylum seekers to seek relocation in those nations as opposed to the US.

Miller has been 'singularly focused on how to get people out of the country'

Stephen Miller talks to reporters about President Donald Trump's immigration system in December 2017. Chip Somodevilla/Getty Images

Miller, a speechwriter on Trump's 2016 campaign, which focused largely on immigration along the nation's southern border, often acted similarly as he spearheaded the administration's immigration policies, sources told the magazine. Miller has been a puppeteer of sorts behind the president's immigration initiatives, which included his almost entire suspension of existing asylum programs in July 2019.

As The Washington Post reported in August last year, Miller had worked to become the defining voice of the Trump administration's immigration policy, with one senior Trump administration official telling the D.C. paper he was "singularly focused on how to get people out of the country."

Following Trump's ascension to the White House, Miller, who had previously worked in the office of then-Sen. Jeff Sessions, didn't desire a high-level Cabinet position. Instead, Miller inquired about which position within the administration had the most power on immigration issues.

In 2017, Miller was an architect behind the executive order that banned travel from Muslim-majority nations, which was expanded in January this year. The executive order, of which the DHS was not given advance notice, sparked protest, outrage, and a contentious weeks long semantics debate over whether the policy was a ban at all.

Miller's uncle David Glosser said he donated to a refugee-rights charity as a wedding gift and in protest of his nephew's political views, Business Insider's Tom Porter reported.

"Protect the refugee and welcome the stranger. They built America," Glosser wrote in a Facebook post, adding that their ancestors were themselves refugees in America.

Glosser wasn't invited to the wedding.

Read more:

Meet Stephen Miller, the 34-year-old White House adviser who's being called to resign after leaked emails showed him sharing white supremacist links

Everything we know about Mike Pence's press secretary Katie Waldman

Stephen Miller's uncle calls him an 'immigration hypocrite' in a scathing op-ed

Trump attended the wedding of Stephen Miller, the staunchest immigration hardliner in the White House