WASHINGTON — Republican U.S. Senator Chuck Grassley is treading carefully around reports a whistleblower in the U.S. intelligence community is alleging serious wrongdoing by President Donald Trump.

Grassley, who calls himself a “longtime champion of whistleblowers,” won’t comment directly on reports President Trump allegedly ordered his staff to withhold $400 million in aid from Ukraine while pressuring that nation’s president to investigate Democratic presidential candidate Joe Biden.

“We don’t know what we don’t know,” Grassley says. “Everything I know about it, as I’ve seen on television or read, I don’t have any inside information so I think that dictates I ought to be very cautious what I say.”

Grassley issued a news release Monday afternoon saying, “rampant speculation by politicians and the media is not helpful. That’s how the false Russia collusion narrative took root. Let’s not repeat the mistakes of the past. Going forward, it’s important to respect the law and the whistleblower’s confidentiality while we gather the facts of the case.”

“My press release was a reminder that I listen to whistleblowers,” Grassley says, “and if this whistleblower wants to talk to me, I’ll talk to him.” Grassley is founder of the bipartisan Senate Whistleblower Protection Caucus and he says whistleblower laws are “critical to providing safe outlets to share information so governmental officials can be held responsible without harming national security.”

“Maybe for two or three decades, the intelligence community wasn’t covered by whistleblowers and I thought that was wrong,” Grassley says. “We do have laws now protecting whistleblowers in the intelligence community.” Grassley says the nation does not need another Edward Snowden situation, “where information is released publicly and our national security is harmed.”

He adds, “transparency is always the best policy so long as we don’t endanger national security.”