President Trump has reversed an Obama-era memorandum dictating how and when the U.S. government can deploy cyberweapons against its adversaries, in an effort to loosen restrictions on such operations, according to people familiar with the action.

Mr. Trump signed an order on Wednesday reversing the classified rules, known as Presidential Policy Directive 20, that had mapped out an elaborate interagency process that must be followed before U.S. use of cyberattacks, particularly those geared at foreign adversaries.

The change was described as an “offensive step forward” by an administration official briefed on the decision, one intended to help support military operations, deter foreign election influence and thwart intellectual property theft by meeting such threats with more forceful responses.

The Trump administration has faced pressure to show that it is taking seriously national-security cyberthreats—particularly those that intelligence officials say are posed by Moscow.

Top administration officials are also devising new penalties that would allow stronger responses to state-sponsored hacks of U.S. critical infrastructure, The Wall Street Journal reported earlier this month, a mounting worry due to Russia’s efforts to penetrate American electric utilities.