WASHINGTON — Secretary of State Mike Pompeo announced on Tuesday that he was lifting the State Department’s hiring freeze, ending the Trump administration’s unpopular effort to slash funding and staffing levels for the United States’ diplomatic corps.

The move, Mr. Pompeo wrote in a morning email to staff, “will give our domestic bureaus and missions overseas the flexibility to fill positions that are essential to promoting the department’s mission and the United States’ foreign policy goals worldwide on behalf of the American people.”

Mr. Pompeo had already ended a hiring freeze on diplomats’ family members — such as husbands, wives and adult children — who work in embassies around the world and generally do so for far less money than normal rates.

The moves have been met with relief by diplomats and State Department observers, who were outraged by former Secretary of State Rex W. Tillerson’s attempts to severely cut the department’s budget and staffing.