Former media mogul Conrad Black says Donald Trump’s rise in the U.S. from political neophyte to Republican presidential nominee is an “amazing achievement.”

Speaking on CTV News Channel on Friday, Black said no one “has ever run a campaign like this,” referring to Trump’s rise from businessman and reality TV star to a serious candidate who could be elected U.S. president in November.

“Whatever the outcome, what Donald’s done, it’s an amazing achievement,” Black said.

Black says he is not a “staunch supporter of Trump” but a “defender against excessive denigration” of the Republican presidential nominee.

Trump was “completely reviled and ridiculed by virtually everyone as a candidate who had no chance,” Black said.

Now, as the U.S. campaign enters its final three-month stretch, Trump is viewed as a serious threat to Democratic presidential nominee Hillary Clinton’s bid for the White House.

“They’re running even in the polls, there is no split in the Republican party and the Democrats opened their convention by firing their party chairman,” Black said. “It’s going to be a ding-dong battle, this election.”

Black shrugged off former New York City Mayor Michael Bloomberg’s criticism of Trump’s business acumen in a speech at the Democratic National Convention earlier this week. In it, Bloomberg called Trump’s business plan a “disaster in the making.”

Black wouldn’t “attach much credence” to Bloomberg’s assertion that Trump will “wreck” the U.S., he said. He says that if elected, Trump will produce “more sensible economic policy” than what the U.S. has seen over the past decade.

Though he finds some of Trump’s “reflections garish and tasteless,” Black says the presidential candidate is a “nice guy.”

“I will say this, that in the problems I had, he was absolutely loyal, he volunteered to come and give evidence for me, he sent me encouraging letters at every stage,” Black said. “We all go through difficult times and we remember the people who were helpful.”

However, Black said that he doesn’t “identify” with some of Trump’s comments and “demonstrations of ill-temperance.”

“It’s not a person I recognize, knowing him as I do, he’s not like that in person,” Black said. “He’s a very nice guy, and a charming man.”