AT&T plans to close its purchase of Time Warner no later than June 20 after a U.S. court decided it could move ahead with the deal, the company's lead attorney said on Tuesday.

U.S. District Judge Richard Leon strongly urged the Justice Department not to seek an emergency stay of the ruling, which could prevent AT&T from the closing the transaction ahead of a June 21 contractual deadline with Time Warner to complete the purchase.

"The judge's sweeping rejection of the government's case doesn't surprise us at all," AT&T attorney Daniel Petrocelli told reporters outside of the courthouse shortly after the decision was issued.