Top Defense officials are considering breaking the National Security Agency (NSA) away from the Cyber Command (CYBERCOM), a move that the chairman of the House Armed Services Committee said made him "profoundly concerned."

Rep. Adam Smith, D- Wash., sent a letter to acting Department of Defense Secretary Christopher Miller, objecting to the department’s attempts to separate the security commands "without consulting Congress or meeting the conditions required by law."

The NSA and CYBERCOM work closely together under the Department of Defense, and are both overseen by four star Gen. Paul M. Nakasone.

The push to separate them during President Trump’s final days in office, is the latest move by the Trump administration to shake up the Pentagon.

Miller was named acting secretary in early November, after Trump unexpectedly sacked Defense Secretary Mark Esper.

Esper had condemned the use of the Insurrection Act during nationwide protests this summer. The 1807 Act would have allowed Trump to deploy National Guard troops within the U.S.

Miller continued the Pentagon shake-up by hiring loyal Trump officials and firing head of the Pentagon’s Defeat ISIS Task Force Christopher P. Maier, earlier this month. The U.S. also withdrew thousands of troops from the Middle East and Africa.

Smith’s letter Thursday condemned not only the apparent method considered for the cyber defense split, but the timing.

"Any action to sever the dual-hat relationship could have grave impacts on our national security, especially during a time that the country is wrestling with what may be the most damaging cyber-attack in our country’s history," he wrote in his letter to Miller and chairman of the Joint Chiefs of Staff, Army Gen. Mark Milley.

Cybersecurity officials in the U.S. currently are addressing a high level breach that compromised federal agencies’ "critical infrastructure," according the Department of Homeland Security earlier this week.

The department has not revealed which agencies were targeted or the extent of the breach, only noting the "threat poses a grave risk to the Federal Government and state, local, tribal, and territorial governments as well as critical infrastructure entities and other private sector organizations."

"CISA (Cybersecurity and Infrastructure Security Agency) expects that removing this threat actor from compromised environments will be highly complex and challenging for organizations," the alert issued Thursday, said.

Secretary of State Mike Pompeo linked the attacks with Russia. But Trump, speaking out Saturday for the first time following the attacks, contradicted Pompeo and came to Russia’s defense, instead accusing China.

"Russia, Russia, Russia is the priority chant when anything happens because Lamestream is, for mostly financial reasons, petrified of discussing the possibility that it may be China (it may!)," Trump wrote on Twitter, downplaying the severity of the attack.

In his letter, Smith noted that there are steps the DOD must take in order to separate the NSA and CYBERCOM – a measure Congress actually worked to reinforce in 2019 following chatter about a potential split, reported Defense News.

"Given that no assessment has been completed and no certification has been issued, I remind you that any action to terminate the dual-hat relationship with NSA and Cyber Command is not only inadvisable, but is contrary to law," Smith wrote.