Twitter Chief Executive Officer Jack Dorsey on Wednesday told United States legislators that the social media network was “unprepared and ill-equipped” for the misinformation campaigns that have plagued it for the last few years.

Dorsey and Facebook Chief Operating Officer Sheryl Sandberg appeared before the US Senate Intelligence Committee to testify about alleged foreign interference via social media in American elections, as well as about other malicious behaviour often seen on these platforms.

Dorsey also live-tweeted his opening statement. Dorsey said that the social media platform was meant to be a “public square”, but failed to deal with “abuse, harassment, troll armies, propaganda through bots, misinformation campaigns, and divisive filter bubbles”.

“We aren’t proud of how that free and open exchange has been weaponised and used to distract and divide people, and our nation [the US],” he told senators. “We found ourselves unprepared and ill-equipped for the immensity of the problems we’ve acknowledged.”

“We’ve learned from 2016 [US presidential polls] and more recently from other nation’s elections how to help protect the integrity of our elections,” Dorsey said. He added that Twitter has made progress on solutions to the problem, “like identification of many forms of manipulation intending to artificially amplify information, more transparency around who buys ads and how they are targeted, and challenging suspicious logins and account creation”.

“We’re now removing over 200% more accounts for violating our policies,” the Twitter CEO added. “We’re identifying and challenging 8-10 million suspicious accounts every week.”

He added: “And we’re thwarting over a half million accounts from logging in to Twitter every day.” Dorsey also rejected allegations that Twitter operates on the basis of political bias, AFP reported.

Facebook also testifies, but Google sends written statement

Facebook Chief Operating Officer Sheryl Sandberg acknowledged that the social media network failed to crack down on attempts from Russia to influence the 2016 US presidential elections, according to AFP. “We were too slow to spot this and too slow to act,” Sandberg told the panel. “This interference was completely unacceptable. It violated the values of our company and of the country we love.”

Google, which was also invited to the hearing, did not send a representative. The company’s Chief Legal Officer Kent Walker sent a written statement, promising to maintain efforts to thwart foreign interference in US elections.

Democratic Party Senator Mark Warner said that he was skeptical that Facebook and Twitter would be able to address the problems of manipulation on their own. “Congress is going to have to take action here,” he said.