Internet service providers have warned that harsh regulation on net neutrality could affect Internet infrastructure investment. AT&T is now making that a reality.

AT&T CEO Randall Stephenson said on Wednesday that the company is putting a hold on the buildout of its fiber network until the Federal Communications Commission comes to a decision on net neutrality regulations.

The announcement comes just a day after President Obama came out firmly in favor of reclassification, a move that would give the FCC greater regulatory power over Internet service providers (ISPs) like AT&T. ISPs have rallied hard against this plan.

"We can't go out and invest that kind of money deploying fiber to 100 cities not knowing under what rules those investments will be governed," Stephenson said during a a conference.

"We think it is prudent to just pause and make sure we have line of sight and understanding as to what those rules would look like," he said.