U.S. Defense Secretary Lloyd Austin, Australian Defense Minister Richard Marles and Japanese Defense Minister Gen Nakatani held a press conference Sunday following their trilateral defense ministers meeting in Darwin, Australia.

The three leaders were asked about how they think President-elect Donald Trump's administration will affect the war in Ukraine, defense secretary nominee Pete Hegseth's qualifications to lead the Department of Defense and the North Korean troops deployed to fight alongside the Russian military in Ukraine.

Marles said he looks "forward to building a relationship" with Hegseth, calling the defense secretary position a "huge global role," and said the Fox News host has "an enormous challenge ahead of him."

"Everything that I've heard about Pete Hegseth since his name became public, is in terms of in the context of becoming the secretary of defense, has been positive, and I approached the prospect of getting to know Pete Hegseth and working with him with enormous optimism," Marles said.

Austin said, "it's the prerogative the president elect to nominate whoever he deems appropriate to serve on his cabinet," and that the Pentagon is "focused on a smooth and an effective transition."

-ABC News' Nathan Luna

President-elect Donald Trump announced Saturday that Chris Wright is his nominee to lead the Department of Energy.

Wright, who must be approved by the Senate, is the chief executive of Liberty Energy – the world’s second-largest fracking services company – and is one of the industry’s most outspoken critics of the effort to combat climate change.

"There is no climate crisis, and we're not in the midst of an energy transition either," Wright said in a video posted to LinkedIn last year.

A 2021 study published in the environmental journal Environmental Research Letters, found that 99% of climate scientists agree that humans are causing global warming and climate change.

"I think by far the biggest challenge with climate change today is policies pursued in the name of climate change that make energy more expensive and less reliable," Wright told the Heritage Foundation last year.

According to the World Resources Institute, “solar and wind now provide the cheapest power for 67% of the world” and in the United States, wind is the cheapest source of new bulk electricity per megawatt-hour.

"As Secretary of Energy, Chris will be a key leader, driving innovation, cutting red tape, and ushering in a new 'Golden Age of American Prosperity and Global Peace,'" Trump said.

-ABC News' Lalee Ibssa, Peter Charalambous and Matthew Glasser

President-elect Donald Trump announced Saturday that William Owen Scharf, an attorney who represented him in several cases including the Supreme Court case involving presidential immunity, will serve as assistant to the president and White House staff secretary.

"Will is a highly skilled attorney who will be a crucial part of my White House team," Trump said in a Truth Social Post.

-ABC News' Lalee Ibssa

President-elect Donald Trump is expected to attend Saturday night’s UFC Fight: UFC 309: Jon Jones vs. Stipe Miocic at Madison Square Garden, a source familiar with Trump's planning told ABC News.

He is planning on spending the night in New York on Saturday and will return to Florida on Sunday, according to the source.

-ABC News' Lalee Ibssa, Soo Rin Kim and Kelsey Walsh