The White House’s cybersecurity coordinator said Thursday that he is stepping down at the end of this month after a 2 1 / 2-year tenure in which the administration has increased its focus on cyber issues but struggled to reach agreement with lawmakers on the best way to protect the nation’s key computer networks from attack.

Howard Schmidt, who oversaw the creation of the White House’s first legislative proposal on cybersecurity, said he is retiring to spend more time with his family and to pursue teaching in the cyber field.

Schmidt leaves at a time when the administration still has much work to do to ensure the protection of the computer systems of companies that provide electricity and other critical services. He will be succeeded by Michael Daniel, chief of the White House budget office’s intelligence branch.

Daniel has worked at the Office of Management and Budget for 17 years, the past 10 handling cybersecurity issues.

Schmidt, 62, who also served a turn as a White House adviser on cyber issues during the administration of President George W. Bush, had signed up for a two-year-stint, officials said. It was a job few wanted, seeing it as a position with much responsibility but little real authority.

“We prevailed on him to spend a few more months,” White House counterterrorism adviser John O. Brennan said Thursday.

Schmidt, a former Air Force officer and chief information security officer at Microsoft, said the job came with built-in authority. “When you’ve got the president directing you to do something, I don’t know how clout gets any bigger than that,” he said.

During Schmidt’s tenure, the White House unveiled its first international strategy for cyberspace, which stated that the United States will respond to hostile acts in cyberspace as it would to any other threat to the country, reserving the right to use “all necessary means,” including diplomatic and military, to defend the country.

Schmidt also led the creation of the National Strategy for Trusted Identities in Cyberspace — a program aimed at developing methods for people and businesses to authenticate their identities online that are safer than using passwords, which can be stolen by hackers.

The United States’ growing dependence on digital networks for daily commerce, energy production and military operations has made cybersecurity a prime national-security issue.

In May 2009, President Obama declared networks that handle data for such purposes a “strategic national asset” and warned that the cyberthreat was one of the most serious economic and national security challenges the nation faced. Other officials say it could overtake terrorism as the top threat to the country.

Brennan said that Schmidt and his team have worked to identify vulnerabilities in the nation’s critical systems and identified resources to address them. “On both the threat side and vulnerability side, we have a better appreciation of what we’re dealing with,” he said.

Schmidt’s role has often been overshadowed by that of Keith Alexander, director of the National Security Agency and head of the military’s Cyber Command, with a debate over the role of the NSA in defending private sector networks gaining more public attention.

But Brennan said Schmidt’s role is an important one: to help the government understand how to “prevent intruders from carrying out successful attacks” and to help coordinate the partnership between the NSA and the Department of Homeland Security, which is responsible for protecting critical infrastructure.

Schmidt’s leadership “has made a difference both within the federal government and throughout the nation, and he will be missed,” Alexander said in a statement.

At OMB, Daniel, 41, played a key role in shaping intelligence budgets and has worked on every major issue affecting the intelligence community, including implementing intelligence reforms after the 2001 terrorist attacks, officials said. He has coordinated funding for the Comprehensive National Cybersecurity Initiative, begun under the Bush administration.

At the end of May, Schmidt said he will ride his Harley-Davidson motorcycle west. His home is near Seattle, and he has extended family in Wisconsin, including a sixth grandchild on the way.