Former Immigration and Customs Enforcement Director Tom Homan, Trump's newly announced " border czar," said his main priority will be overseeing and formulating Trump's long-vowed mass deportation strategy while consolidating decisions related to border security.

"Everybody talks about this mass deportation operation. President Trump talks about. I'll oversee that and come up with a strategy for that," Homan said during a lengthy interview with his hometown television station WWNY on Monday.

Homan said Trump's mass deportations is "going to be a targeted enforcement operation, concentrating on criminals and national security threats first."

He acknowledged that the deportations would be costly but argued the policy would "save the taxpayers a lot of money."

Homan said he does not plan to "separate women and children" but acknowledged that deporting alleged criminals would result in breaking up families.

"When we arrest parents here, guess what? We separate them. The illegal aliens should be no different," Homan said.

Homan also said worksite enforcement -- an aspect of immigration policy focused on unauthorized workers and employers who knowingly hire them -- is "going to get fired back up."

"Under President Trump, we're going to work it and we're going to work it hard," he said.

-ABC News' Peter Charalambous

Melania Trump is not expected to travel to Washington with President-elect Donald Trump on Wednesday, two sources told ABC News.

First lady Jill Biden had extended an invite to Melania Trump for a meeting, according to the sources. In 2016, Michelle Obama had hosted Melania Trump at the White House.

The Trump campaign declined to comment. The first lady’s office confirmed to ABC News that a joint invitation was extended to the Trumps to meet at the White House though declined to comment beyond that.

-ABC News' Rachel Scott, John Santucci and Molly Nagle

Robert F. Kennedy Jr. has continued to broadly advise Trump and the transition team on health-related appointments and has been in discussions to possibly fill a major role in the next administration, sources familiar with the matter told ABC News.

While sources caution that a role has not been finalized, RFK Jr. has been discussed as a potential candidate for the next secretary of Health and Human Services. But other roles are also on the table, including a broad "czar"-like position that would advise on policy and personnel decisions in other health arenas, the sources said.

RFK Jr. has been in active discussions with the transition team since Trump's election victory last week. He's been spotted at Trump's Mar-a-Lago club multiple times and has been engaging in presentations which include candidates for specific Cabinet and health-related jobs, sources said.

He has spent hours with the co-heads of Trump's transition team -- billionaire Howard Lutnick and Linda McMahon -- in addition to others at Mar-a-Lago such as Trump's son Donald Trump Jr.; investor and donor Omeed Malik; Tucker Carlson; and Del Bigtree, RFK Jr.'s former campaign spokesperson who produced a documentary called "Vaxxed: From Cover-Up to Catastrophe."

-ABC News' Katherine Faulders, Olivia Rubin and Will McDuffie

President-elect Donald Trump has tapped former New York Rep. Lee Zeldin to lead the Environmental Protection Agency.

"Lee, with a very strong legal background, has been a true fighter for America First policies," Trump said in a statement. "He will ensure fair and swift deregulatory decisions that will be enacted in a way to unleash the power of American businesses, while at the same time maintaining the highest environmental standards, including the cleanest air and water on the planet. He will set new standards on environmental review and maintenance, that will allow the United States to grow in a healthy and well-structured way."

Zeldin, who also ran for New York governor against Andrew Cuomo in 2022, confirmed he had been offered the job via a post on X.

"It is an honor to join President Trump’s Cabinet as EPA Administrator," he wrote. "We will restore US energy dominance, revitalize our auto industry to bring back American jobs, and make the US the global leader of AI. We will do so while protecting access to clean air and water."

-ABC News' John Santucci, Rachel Scott and Katherine Faulders

As Trump continues to round out his cabinet, the job of treasury secretary remains in flux, with the co-chair of Trump's transition team actively vying for the job, sources familiar with the matter told ABC News.

Howard Lutnick is looking to be tapped as treasury secretary, sources said, a move that comes as investor and hedge fund manager Scott Bessent is also a top contender for the role.

Bessent traveled to Mar-a-Lago as recently as Friday to meet with Trump about the job, the sources said.

Lutnick, on the other hand, spends hours with Trump nearly each day, presenting candidates for top roles in the administration. As such, the move by Lutnick to attempt to get a cabinet position for himself has frustrated some close to Trump.

Sources caution the job is still in flux and neither man could get the job -- with the potential for other candidates to emerge.

One potential dark horse for the job, one source told ABC News, is former Trump administration trade representative Robert Lighthizer, who Trump sees as an aggressive advocate for his tariff-heavy approach to international trade.

-ABC News' Jonathan Karl, Olivia Rubin and Katherine Faulders