National Security Director Adm. Mike Rogers said Monday that the leak of surveilled transcripts that should stay classified is an act that can “hurt” U.S. national security.

Rogers was pressed on the issue by Rep. Tom Rooney, R-Fla., who was asking about the leak of a wiretapped conversation between former national security adviser Mike Flynn and the Russian ambassador to the U.S., Sergei Kislyak. That leak contributed to Flynn’s decision to step down in the first few weeks of the Trump administration.