House Speaker Mike Johnson expressed deep concerns Sunday about a major leak of US intelligence detailing Israel’s plans to retaliate against Iran and stressed that he’s following the situation “closely.”

Johnson (R-La.), who is on the campaign trail in Michigan, talked with Israeli Prime Minister Benjamin Netanyahu and said that he will receive a “classified-level” briefing on the leak later in the day.

“The leak is very concerning. There’s some serious allegations being made there, an investigation underway, and I’ll get a briefing on that in a couple of hours,” Johnson told CNN’s “State of the Union. “We’re following it closely.”

“I talked to my friend … Prime Minister Netanyahu, yesterday to encourage him,” he added. ” I think that the United States needs to stand unequivocally by our ally there… we’re on a precipice… of a new era of security and freedom for Israel. And I think we’re very close.”