(CNN) CNN's Anderson Cooper questioned Wednesday how President Donald Trump could say Susan Rice is the biggest story of the moment, just one day after the deadliest chemical gas attack Syria has seen in years.

"If so many things are described as the biggest, or the best, or the most -- how to tell what really is important to this president?" Cooper said.

Trump told the New York Times that former national security adviser Susan Rice may have committed a crime by requesting the names of Trump associates who were incidentally mentioned on intercepted communications during the Obama administration. The President offered no evidence to back up the allegation.

"I think the Susan Rice thing is a massive story," he told the newspaper . "I think it's a massive, massive story ... I think it's going to be the biggest story."

Cooper said that Trump's remarks came off as tone deaf a day after scores of civilians were killed in a suspected chemical attack in Syria.

"He was not talking about Syria, about the wholesale slaughter that has been going on for years now or about the chemical attack that took place just yesterday." Cooper said. "No, he was talking about Susan Rice."

"Now, whatever you think the former White House National Security Adviser has done wrong -- if in fact she's done anything wrong at all -- it's hard to imagine it could possibly amount to the biggest anything," Cooper continued. "Particularly on a day when the international community and the President himself are coming to terms with the fact that at least 70 people were killed in a poison gas attack in Syria."

Trump addressed the attack in a news conference earlier Wednesday, saying that the attack "crossed a lot of lines" for him.

""These heinous actions by the Assad regime cannot be tolerated," Trump said from the Rose Garden. "The United States stands with our allies across the globe to condemn this horrific attack and all other horrific attacks, for that matter."