Time to testify:Mark Zuckerberg leaving a meeting on Capitol Hill, Washington, on Monday.APJ. Scott Applewhite  

Facebook Inc’s chief executive Mark Zuckerberg told Congress on Monday that the social media network should have done more to prevent itself and its members’ data being misused and offered a broad apology to lawmakers.

His conciliatory tone precedes two days of Congressional hearings where Mr. Zuckerberg is set to answer questions about Facebook user data being improperly appropriated by a political consultancy and the role the network played in the U.S. 2016 election.

‘A big mistake’

“We didn’t take a broad enough view of our responsibility, and that was a big mistake,” he said in remarks released by the U.S. House Energy and Commerce Committee on Monday. “It was my mistake, and I’m sorry. I started Facebook, I run it, and I’m responsible for what happens here.”

Mr. Zuckerberg was meeting with lawmakers on Capitol Hill on Monday ahead of his scheduled appearance before two Congressional committees on Tuesday and Wednesday.

Top of the agenda in the forthcoming hearings will be Facebook’s admission that the personal information of up to 87 million users, mostly in the U.S., may have been improperly shared with political consultancy Cambridge Analytica.

But lawmakers are also expected to press him on a range of issues, including the 2016 election. “Its clear now that we didn’t do enough to prevent these tools from being used for harm...” his testimony continued.

“That goes for fake news, foreign interference in elections, and hate speech, as well as developers and data privacy.”

Facebook, which has 2.1 billion monthly active users, said on Sunday that it plans tell users users whose data may have been shared with Cambridge Analytica. Facebook has about 15,000 people working on security and content review, rising to more than 20,000 by the end of 2018, Mr. Zuckerberg’s testimony said.