In an interview with Axios's Mike Allen on Thursday, Facebook COO Sheryl Sandberg said the social network owes America an apology for its role in enabling Russian meddling in the 2016 presidential election.

"Things happened on our platform that shouldn't have happened," she said in reference to the events leading up to the election. "We know we have a responsibility to prevent everything we can from this happening on our platforms."

In September, Facebook announced that 470 Russian-linked accounts had purchased about 3,000 advertisements that used divisive issues like race, religion, immigration, and gun control to rile users. Facebook gave the ads to the Senate Intelligence Committee, which were viewed by about 10 million U.S. users, and will testify at a public hearing on Nov. 1. Sandberg told Allen that the company would continue to cooperate with lawmakers' requests for information. "We'll do everything we can to defeat them," she said.

Sandberg admitted that the Russian-financed ads and fake news are a "new threat" that Facebook must address and accept responsibility for, but she offered some exceptions. If the Russian-linked ads were posted by real people and not bots or fake accounts, Facebook must leave them up on the site. "When you allow free expression, you allow free expression," Sandberg said.