WASHINGTON, July 24 (Xinhua) -- U.S. Treasury Secretary Steven Mnuchin said Wednesday that Amazon has reduced competition and "destroyed" the country's retail industry, lauding the Department of Justice (DOJ) efforts to look into big technology companies.

"I think if you look at Amazon, although there are certain benefits to it, they've destroyed the retail industry across the United States so there's no question they've limited competition," Mnuchin told CNBC's "Squawk Box".

The DOJ announced Tuesday that it is opening an antitrust review to determine whether "market-leading" online platforms are unlawfully stifling competition, which is expected to rattle tech giants such as Amazon, Apple, Facebook and Google.

The review will consider the "widespread concerns" that consumers, businesses and entrepreneurs have expressed about internet search, social media, and some retail services online, the statement said.

"I think it's very good that the attorney general is going to look into this," Mnuchin said. "I think it's an important issue and I look forward to him reporting back to the president and hearing his recommendations."

In response to Mnuchin's remarks that Amazon hurts small businesses in some areas, the online retail giant told CNBC that small and medium-sized businesses are "thriving" with Amazon. "Today, independent sellers make up more than 58 percent of physical gross merchandise sales on Amazon, and their sales have grown twice as fast as our own," it said.

Growing concerns about the power of major tech companies have prompted both congressional Democrats and Republicans to call for more regulatory scrutiny, and even U.S. President Donald Trump has recently intensified his criticism, again claiming that social media companies are biased against conservatives.

Last week, the U.S. House Judiciary Committee held a hearing on the power of the online platform companies, as executives from the four tech giants took tough questions from committee members on competition and innovation.