Mark Zuckerberg accepted personal responsibility for the leak of users' data.

(AFP)New Delhi/Washington:  Facebook founder Mark Zuckerberg on Tuesday told US Congress that he took personal responsibility for the leak of data on tens of millions of its users, and assured the senate that his company will do "everything" to ensure the upcoming elections in India and other countries are safe."2018 is an important year for the whole world.

Several countries like India, Pakistan will have elections.

We'll do everything possible to ensure these elections are safe," Mr Zuckerberg said during the hearing.The Facebook chief has been under mounting preassure over the hijacking of its user data by Cambridge Analytica, a British political consultant firm.Cambridge Analytica is reported to have been involved in "all kind of projects" in India and had major political parties like Congress as it clients.

Christopher Wylie, a former Cambridge Analytica employee, had told a British parliamentary committee that the British firm even has an office in India. Mark Zuckerberg took responsibility for the missteps in his testimony (Reuters)"I believe their client was Congress.

But I know that they have done all kind of projects.

I don't remember any national project, but regionally India is so big that one state can be the size of Britain.

They do have offices there, staff there.

I believe I have some documentation on India which I can provide if you're interested," the 28-year-old said.

In his first formal congressional appearance, the Facebook chief sought to quell the storm over privacy and security lapses at the social media giant that have angered lawmakers and the network's two billion users."It was my mistake, and I'm sorry," Mr Zuckerberg said.

"I started Facebook, I run it, and I'm responsible for what happens here."It's clear now that we didn't do enough to prevent these tools from being used for harm," he said.

"That goes for fake news, foreign interference in elections, and hate speech, as well as developers and data privacy." The 138-seat hearing room on the second floor of Capitol Hill where Mark Zuckerberg testified (Reuters)The 33-year-old CEO spoke of a constant struggle to guard against Russian manipulation of the Facebook platform to influence elections in the US and elsewhere."There are people in Russia whose job it is to try to exploit our systems and other internet systems and other systems as well," he said."So this is an arms race.

They're going to keep getting better and we need to invest in getting better at this too."Mr Zuckerberg has previously acknowledged the social network failed to do enough to prevent the spread of disinformation during the last US presidential race.He also revealed that Facebook is cooperating with the US special prosecutor investigating Russian interference in the 2016 vote.The social media giant has taken out full-page apology ads in several major US and UK newspapers, including the New York Times, Wall Street Journal and The Washington Post.(with inputs from agencies)