U.S. President-elect Donald Trump's choices to lead the Department of Defense and the Central Intelligence Agency distanced themselves from the incoming president by advocating a tougher approach toward Russia during congressional testimony Thursday.
Republican Congressman Mike Pompeo, Trump's nominee to head the CIA, said Russian interference in the 2016 U.S. presidential election "was an aggressive action taken by the senior leadership inside of Russia," and he called for an "incredibly robust American response."
Pompeo's remarks before the Senate Select Committee on Intelligence come amid a tense standoff between Trump and the intelligence community over Russia's computer hacking during the election.
Trump has frequently criticized the U.S. intelligence community, and speculated that the agencies were responsible for leaking unsubstantiated allegations about his ties to Russia. But Pompeo told lawmakers he sees "nothing to cast any doubt on" the intelligence community's conclusion that Russia was responsible for the cyberattacks.
Mattis speaks out
Trump's nominee to lead the Pentagon, retired Marine General James Mattis, testified before the Senate Armed Services Committee that the global balance of power established after the second world war is being threatened more than ever, in part, by Russia.
“I think its under the biggest attack since World War II, sir, and that’s from Russia, from terrorist groups and with what China is doing in the South China Sea,” Mattis said.
Mattis went on to say "deterrence is critical right now," but added that the U.S. armed forces are not currently strong enough to meet the challenges.
He told lawmakers that Russian President Vladimir Putin "is trying to break the north Atlantic alliance [NATO]," a campaign that requires the U.S. and its allies to defend themselves with an integrated diplomatic, economic and military response.
Mattis said he favors exploring areas of cooperation with Russia, "but we also have to recognize reality and what Russia is up to and there is a decreasing number of areas where we can engage cooperatively and an increasing number of areas where were are going to have to confront Russia."
Mattis testified he and the president-elect have discussed the importance of the NATO alliance, which he described as the most successful military alliance "probably ever."
Mattis has expressed concerns about security threats posed by Iran, and has said he does not support enhanced interrogation techniques, such as waterboarding.
If confirmed by the Senate, Mattis would become the first career military member to lead the Pentagon in more than 50 years. He retired from the U.S. Marine Corps in 2013 after serving as the head of U.S. Central Command and leading forces during the war in Afghanistan and two wars in Iraq.
A law bars military officers from becoming defense secretary until they have been retired for at least seven years, so Congress will have to pass legislation granting a one-time exception for Mattis.
The Senate overwhelmingly approved a waiver for Mattis on Thursday, followed a few hours later by the House Armed Services Committee. But the entire House would have to approve the bill for Mattis to become defense secretary.
The only other U.S. Secretary of Defense to have gotten the retirement waiver was the legendary Army General George C. Marshall in 1950.
WATCH: Mattis responds to question about sanctions against Russia
Pompeo, Carson hearings
Pompeo has criticized President Barack Obama's administration for reining in interrogation techniques, saying the methods were "within the law, within the Constitution, and conducted with the full knowledge" of appropriate lawmakers.
Pompeo, a graduate of Harvard Law School and the West Point military academy, drew criticism in 2013 after he suggested Muslim leaders who don't publicly condemn terror attacks are "potentially complicit" in the attacks.
WATCH: Pompeo on Russian cyber threats, hacking report
At a third confirmation hearing Thursday, the man who is up for the job of leading the Department of Housing and Urban Development declined to guarantee that no money from the agency would benefit the resident-elect or his family, which own and operate a global real-estate business.
"It will not be my intention to do anything to benefit any American. It's for all Americans, everything that we do," Ben Carson, a celebrated retired neurosurgeon, said before the Senate Banking Committee.
After Trump took the lead in the race about a month after he declared he was running for president, Carson was the only challenger in the Republican field who managed to pull ahead of him in national polls, though that lasted only a few days. He supported Trump quickly after dropping out of the race.
Carson lacks public policy experience, but a collection of former HUD secretaries who served under Presidents Bill Clinton and George W. Bush wrote a letter to the committee stating they believe he would listen to the agency's civil servants to help create affordable homes and inclusive communities.
In the past, Carson has voiced opposition to government programs that encourage what he says is "dependency," and has touted the virtues of individual effort in becoming successful.
Trump tweeted his praise for his Cabinet nominees Friday morning.
All of my Cabinet nominee are looking good and doing a great job. I want them to be themselves and express their own thoughts, not mine!— Donald J. Trump (@realDonaldTrump) January 13, 2017
VOA’s Kenneth Schwartz contributed to this report.