Facebook chief executive Mark Zuckerberg has stood by his company's decision to run political adverts after Twitter announced it would ban them.

Twitter boss Jack Dorsey said in a series of tweets yesterday that all political advertising on the social media platform would cease on 22 November.

It came as Facebook faced criticism after disclosing it would not fact-check most political ads, instead only banning adverts containing claims debunked by third-party fact-checkers.

Less than an hour after Mr Dorsey's announcement, Mr Zuckerberg spoke about what he said was Facebook's deep belief "that political speech is important" and stood by his company's decision.

"Some people accuse us of allowing speech because they think all we care about is making money, and that's wrong," he said in a Facebook earnings conference call after the Twitter announcement.

"I can assure you that, from a business perspective, the controversy this creates far outweighs the very small percentage of our business that these political ads make up.

"I don't think anyone can say that we are not doing what we believe or we haven't thought hard about these issues."

Earlier this month, Mr Zuckerberg said it is not the job of tech firms to "censor".

Speaking to students at Georgetown University in Washington, Mr Zuckerberg responded to critics who argued that Facebook is enabling political leaders including US President Donald Trump to propagate misinformation.

Mr Zuckerberg said the policy - which does not include the fact-checking of political speech or ads - is based on a long tradition of allowing free expression.

Twitter chief executive Mr Dorsey said political message reach "should be earned, not bought".

He said in a series of tweets: "A political message earns reach when people decide to follow an account or retweet.

"Paying for reach removes that decision, forcing highly optimized and targeted political messages on people. We believe this decision should not be compromised by money."

Facebook's revenue in the past three months was up 29% at $17.7 billion compared with $13.7bn for the same period last year, while monthly active users increased by 8% to $2.45bn, its latest financial report shows.

Advertising revenue also increased from $13.5bn to $17.4bn.

US presidential candidate Elizabeth Warren has highlighted her own concerns over Facebook's political advertising policy by paying for a series of adverts which included false claims about Mr Zuckerberg.

The adverts, which successfully appeared on the social network, claimed the Facebook founder had endorsed Mr Trump for re-election next year, before suggesting they had given politicians "free rein to lie" on the platform.