AL MUKALLA, Yemen — Thousands of Yemeni troops are conducting a clearing operation aimed at driving Qaeda militants from one of their major strongholds in southern Yemen, according to Arab and American security officials.

The offensive in Shabwa Province started last week and includes about 2,000 Yemeni forces backed by dozens of advisers from the United Arab Emirates, and a handful of United States Special Operations commandos providing intelligence and planning assistance, American officials said.

It is the largest military operation against Qaeda fighters in Yemen since Yemeni troops in armored vehicles and backed by airstrikes seized this major port city in April 2016, after the militants had used it as a base from which to storm through the southern part of the country.

The continuing operation is the latest phase of an increased campaign against the Yemeni militants since President Trump took office. It also reflects Mr. Trump’s general embrace of President Barack Obama’s strategy to aid local allies fighting insurgents in hot spots like Yemen, Somalia and Nigeria, rather than dispatch large numbers of American troops.