Secretary of State Rex Tillerson says the United States is convinced that the incidents harming the health of U.S. Embassy workers in Cuba were “targeted attacks.”

Tillerson is pushing back on Cuba’s complaints that the U.S. hasn’t shared enough information to let Cuban authorities investigate. He says the U.S. has shared some information but that he’s put two restrictions in place.

Tillerson says he won’t share information that violates individuals’ privacy or reveals their medical conditions. And he says he won’t release information that helps the perpetrator determine how effective the attacks were.

Tillerson says he understands the Cubans don’t like the actions the U.S. has taken in response. But he says the United States doesn’t like having its diplomats come under attack.