With weeks to go in his tenure, President Obama on Friday moved to end the controversial “dual-hat” arrangement under which the National Security Agency and the nation’s cyberwarfare command are headed by the same military officer.

It is unclear whether President-elect Donald Trump will support such a move. A transition official, who spoke on the condition of anonymity to discuss the next administration’s plans, said only that “cybersecurity has been and will be a central focus of the transition effort.”

Pressure had grown on Obama to make such a move on the grounds that the two jobs are too large for one person to handle, that the two organizations have fundamentally different missions and that U.S. Cyber Command, or Cybercom, needed its own leader to become a full-fledged fighting force.

[Obama to be urged to split cyberwar command from NSA

“While the dual-hat arrangement was once appropriate in order to enable a fledgling Cybercom to leverage NSA’s advanced capabilities and expertise, Cybercom has since matured” to the point where it needs its own leader, Obama said in a statement accompanying his signing of the 2017 defense authorization bill.

Cybercom’s mission is, when ordered, to disrupt and destroy adversaries’ networks. It is also to defend the nation against incoming threats to critical systems and to protect the military’s computers from cyberattack.

The NSA also has a defensive mission — to protect the government’s classified networks — but is better known for its role in conducting electronic spying on overseas targets to gather intelligence on adversaries and foreign governments.

Cybercom, established in 2009 inside the NSA headquarters at Fort Meade, Md., has long depended on the spy agency’s capabilities. NSA and Cybercom personnel sit side by side and use the same networks that were built by the NSA.

“The two organizations should have separate leaders who are able to devote themselves to each organization’s respective mission and responsibilities, but should continue to leverage the shared capabilities and synergies developed under the dual-hat arrangement,” Obama wrote.

Defense Secretary Ashton B. Carter and Director of National Intelligence James R. Clapper Jr. earlier recommended to Obama that the two organizations have separate heads.

Obama had been on the verge of ending the dual-hat leadership in late 2013 but was persuaded to hold off when senior officials, including the NSA’s director at the time, Army Gen. Keith B. Alexander, argued that the two agencies needed one leader to ensure that the NSA did not withhold resources from Cybercom.

Others, including a presidential review commission, recommended that each of the two groups have its own leader and that the NSA director be a civilian. Since its inception in 1952, the NSA has been led by military officers.

The bill that Obama signed bars the splitting of the leadership role until the defense secretary and the chairman of the Joint Chiefs of Staff jointly certify that to do so would not diminish Cybercom’s effectiveness.

Obama took a swipe at Congress for imposing that requirement on him.

“The Congress . . . should not place unnecessary and bureaucratic administrative burdens and conditions on ending the dual-hat arrangement at a time when the speed and nature of cyber threats requires agility in making decisions about how best to organize and manage the nation’s cyber capabilities,” he wrote.

Obama said that the Pentagon and the Office of the Director of National Intelligence have planned a “phased” transition during which the NSA can continue to “provide vital operational support” to Cybercom.