(Reuters) - Facebook has announced steps to combat misinformation and voter suppression ahead of the November 2020 U.S. presidential election, on the same day it disclosed the removal of a network of Russian accounts targeting U.S. voters on Instagram.

FILE PHOTO: Facebook Chairman and CEO Mark Zuckerberg addresses the audience on "the challenges of protecting free speech while combating hate speech online, fighting misinformation, and political data privacy and security," at a forum hosted by Georgetown University's Institute of Politics and Public Service (GU Politics) and the McCourt School of Public Policy in Washington, U.S., October 17, 2019. REUTERS/Carlos Jasso

Facebook said on Monday it would increase transparency through measures such as showing more information about the confirmed owner of a Facebook page and more prominently labeling content that independent fact-checkers have marked as false.

The social media giant has come under fire in recent weeks over its policy of exempting ads run by politicians from fact-checking, drawing ire from Democratic presidential candidates Joe Biden and Elizabeth Warren.

Last week, Facebook CEO Mark Zuckerberg defended the policy, saying social media had introduced transformative avenues for speech that should not be shut down.

That same day, the Biden campaign called for the removal of an ad run by a super PAC campaign group, not a politician, that it said contained false claims about the former vice president.

Katie Harbath, Facebook’s head of global elections policy, said in response that if the now inactive ad ran again, it would be sent to Facebook’s third-party fact-checkers.

On Monday, Facebook said would be putting into effect its planned ban on paid ads that tell people in the United States not to vote. Zuckerberg told reporters on a conference call that the ban on voter misinformation would also apply to ads run by politicians.

The company will start labeling state-controlled media on its page and in the site’s ad library. In a blog post, Facebook said it planned to expand this labeling to specific posts on both Facebook and Instagram early next year.

Facebook, Twitter and YouTube, the video-streaming service of Alphabet’s Google, all recently came under scrutiny after showing ads from Chinese state-controlled media that criticized Hong Kong protesters.

This month, the Senate committee investigating Russian interference in the 2016 U.S. election said that the Kremlin’s best-known propaganda arm increased its social media activity after that vote.

“The bottom line here is that elections have changed significantly since 2016 and Facebook has changed too.” Zuckerberg said on Monday.

“We face increasingly sophisticated attacks from nation states like Russia, Iran and China, but I’m confident we’re more prepared.”

Theories that China has interfered in U.S. elections are absurd and laughable, said Chinese Foreign Ministry spokeswoman Hua Chunying at a regular press briefing in Beijing on Tuesday.

If someone says China interfered in the U.S. election, they should provide proof, said Hua. China has never had any interest in interfering with other countries’ internal affairs, she said.

Moscow and Tehran have also repeatedly denied the allegations.

Facebook will introduce a new U.S. presidential candidate spend tracker to show how much they have spent on political ads as part of the company’s efforts to make its ad library easier to use, Zuckerberg said.

Facebook launched an online library of political ads in 2018, but the database has been criticized by researchers as being poorly maintained and failing to provide useful ad targeting information.

The company plans to heighten protection of the Facebook and Instagram accounts of candidates, elected officials and their teams through a program called Facebook Protect. Participants in the program will be required to turn on two-factor authentication and their accounts will be monitored for signs of hacking.