Facebook says it wants to make its platform "hostile" to terrorists after an attack in London left at least seven people dead this weekend.

Simon Milner, the company's director of policy, issued a widely reported statement Sunday that said the social media platform works "aggressively" to remove terrorist content.

"We want Facebook to be a hostile environment for terrorists," he said.

U.K. Prime Minister Theresa May had earlier called for closer regulation of the internet, saying Sunday that terrorists need to be denied the digital tools they use to communicate and plan attacks.

"We cannot allow this ideology the safe space it needs to breed," May said. "Yet that is precisely what the internet and the big companies that provide internet-based services provide."

Related: Can Theresa May use tech to stop terror attacks?

May also said that democratic governments must regulate cyberspace, adding that "we need to do everything we can at home to reduce the risks of extremism online."

Tech companies have increasingly come under pressure in Europe because of the way they handle threats and hate speech.

And Google (GOOG), Apple (AAPL), Facebook (FB), Microsoft (MSFT) and many other services have created encrypted channels that may shield communications from law enforcement.

Milner said Sunday that Facebook alerts authorities if it means preventing a terrorist attack from happening.

"If we become aware of an emergency involving imminent harm to someone's safety, we notify law enforcement," he said in the statement.

Related: Theresa May says the internet must be regulated to prevent terrorism

Nick Pickles, Twitter's head of public policy in the U.K., also defended his company Sunday, telling CNNMoney in a statement that "terrorist content has no place on Twitter."

He added that the company will "never stop working" to prevent events like the London terror attack from happening again.

At least seven people were killed and 48 were wounded Saturday night in London when three men drove a van into pedestrians on London Bridge. They then went on a stabbing spree at nearby bars and restaurants.

The attack happened less than two weeks after 22 people were killed in another attack linked to terrorism at an Ariana Grande concert in Manchester.