U.S. president Donald Trump ordered a senior White House official to pressure the Justice Department to block a merger between AT&T and Time Warner in 2017, according to a report in the New Yorker. 

The move deals a blow to U.S. President Donald Trump's administration which tried to block the deal and likely set off a wave of corporate mergers.

The U.S. Department of Justice will file a lawsuit later on Monday to block AT&T Inc's $85.4 billion acquisition of Time Warner Inc.