Meta, Google, Twitter and Microsoft have agreed to take a tougher stance on misinformation under an updated set of EU rules that could carry heavy fines if they fail to do so, Reuters reported.

The European Commission said more than 30 signatory companies, including advertising agencies, have pledged to comply with the updated Code of Practice on misinformation.

The signatories agree to do more to combat deep fakes, fake accounts and political ads, while noncompliance could result in fines of up to 6 percent of a company's global turnover, an EU official said.

Companies have six months to make good on their promises and will have to submit a progress report in early 2023.

"The new code is a testimony that Europe has learned its lessons and that we are not naive any longer," Commission Vice-President Vera Jourova told a news conference.

The war in Ukraine, the COVID-19 pandemic and Britain's exit from the European Union accelerated the EU's fight against fake news, she said.

"If there is consistent flouting of the rules, we can also think about stopping their access to our space of information," he told the news conference.