George Stephanopoulos will not moderate a Republican presidential debate next winter, part of the fallout from reports that the network's top political anchor contributed $75,000 over a three-year period to the Clinton Foundation.

Stephanopoulos voluntarily stepped away from the Feb. 6 debate, said ABC News spokeswoman Heather Riley on Thursday. It is one of nine debates sanctioned by the Republican National Committee.

The co-host of "Good Morning America" and host of the Sunday morning public affairs program "This Week" earlier had apologized for not disclosing his contributions to his employer and viewers. The three donations of $25,000 each in 2012, 2013 and 2014 were made to the foundation set up by former President Bill Clinton because of the organization's work on global AIDS prevention and deforestation, Stephanopoulos said.

The network news division said in a statement that "we stand behind him."