The Department of Homeland Security said Friday that it will grant an additional 15,000 visas for foreign workers this year, a small reprieve for seasonal employers — including many on Cape Cod and the Islands — facing a labor shortage as the summer tourist season kicks off.

Secretary of Homeland Security Kirstjen M. Nielsen raised the cap on H-2B visas after determining there were not enough qualified US workers to meet the needs of American employers, the department said. The same situation occurred last year, although Homeland Security did not grant extra visas until July.

“The limitations on H-2B visas were originally meant to protect American workers, but when we enter a situation where the program unintentionally harms American businesses it needs to be reformed,’’ Nielsen said in a statement.

“I call on Congress to pass much needed reforms of the program and to expressly set the number of H-2B visas in statute. We are once again in a situation where Congress has passed the buck and turned a decision over to DHS that would be better situated with Congress, who knows the needs of the program,’’ she added.

The visas, for temporary nonagricultural workers, are in addition to the 66,000 visas already issued this year, half of which are designated for the summer season. On Jan. 1, the first day requests could be submitted for those 33,000 slots, the Department of Labor received applications for more than 81,000 H-2B positions — three times the number received on that day the year before. By the end of February, Citizenship and Immigration Services said it had enough petitions to meet the cap.

The huge increase in demand for foreign workers has been fueled by a low national unemployment rate and a dearth of Americans willing to work as seasonal housekeepers and cooks. Businesses on the Cape and Islands applied for more than 2,500 H-2B workers this year, according to a Boston Globe review of Labor Department data, but were expected to only get half that number.

The labor crunch drove a number of Cape Cod employers to seek out workers in Puerto Rico over the past few months, many of whom lost their jobs following Hurricane Maria and don’t need visas to work in the United States. Some traveled to the island to recruit workers but came back largely empty-handed, while others forked over up to $2,000 per worker to recruiters to find Puerto Rican employees.

Katie Johnston can be reached at katie.johnston@globe.com. Follow her on Twitter @ktkjohnston.