On "Fox News Sunday," Florida Rep. Mike Waltz -- President-elect Donald Trump’s pick for national security adviser -- confirmed he met with Jake Sullivan, who currently holds the role in President Joe Biden's administration, and said that their teams are working together.

Waltz appeared to defend Biden's weapons policy reversals for Ukraine, though he called the moves "an escalation."

"Look, this is a clear escalation. And the concern has been, where is this escalation going?” Waltz said. "This was in response to, in large part, to North Korea sending troops. We've now responded by allowing these strikes deeper into Russia."

-ABC News' Fritz Farrow

President-elect Donald Trump announced Saturday that Brooke Rollins is his pick to lead the Department of Agriculture.

The seat requires Senate approval.

Rollins served in the first Trump administration, first as the assistant to the president for intergovernmental and technology initiatives and then later as the acting director of the Domestic Policy Council.

After Trump left office, she became the president and CEO of the America First Policy Institute, a conservative right-wing think tank which is made up of former Trump staff members that promotes his agenda.

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

President-elect Donald Trump is already leveraging his endorsement powers to fill vacated House seats around the country as he pulls members of Congress into his cabinet.

Trump encouraged Florida state Sen. Randy Fine to launch a bid for Florida's 6th District seat. Rep. Mike Waltz currently holds the seat, but Trump has tapped him as national security adviser.

"Randy Fine has my Complete and Total Endorsement. RUN, RANDY, RUN!" Trump said in a Truth Social post.

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

President-elect Donald Trump met with the new NATO Secretary General Mark Rutte Friday night at Mar-a-Lago, a NATO spokesperson said.

"They discussed the range of global security issues facing the Alliance," they said.

"The Secretary General and his team also met with Congressman Mike Waltz and members of the President-elect’s national security team," the spokesperson added.

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

In a fiery floor speech on Wednesday, North Carolina Sen. Thom Tillis took his GOP colleagues to task for missing votes on Monday that he said could have helped Republicans block the Democratic effort to install lame-duck lifetime judiciary appointments.

Trump has made clear he wants Republicans to make every effort to block Democrats from advancing judicial nominations.

The Senate is again expected to be in quite late Wednesday evening trying to process judicial nominations, a process necessary because Republicans are objecting to placing votes on these nominees on the Senate calendar.

Republicans will be powerless to stop this if all Democrats show up to vote, as Democrats have the majority necessary to move nominees through. But there were enough Democratic absences on Monday that a full Republican showing could have defeated some of the nominations.

Tillis didn't mince words on the Senate floor Wednesday as he called out his colleagues for missing votes.

"I think the American people are on board with me: We have to show up for work, right?" he said.

"We've got work to do here and I understand there are all kinds of good reasons but there's no excuse to let Chuck Schumer force these judicial nominations down our throat," Tillis said. "We've got to show up for work."

-ABC News' Allison Pecorin