Facebook on Wednesday said it was strengthening how it verifies which groups and people place political advertising on its site, as the social network braces for the 2020 presidential election in the US and works to reduce the spread of online disinformation.

The moves build on rules that Facebook introduced last year, in which it began requiring political advertisers to divulge the name of the organisations responsible for ads on its platform and to prove their identities. Facebook enacted that policy after being criticised for allowing Russian operatives to manipulate its ads in the 2016 American presidential election to divide voters.

Under the new rules, Facebook said that advertisers will need to further demonstrate that they are registered with the US government. That would require submitting proof such as an employer identification number, a Federal Election Commission identification number, or a government website domain.

Smaller businesses will need to provide a verifiable phone number and business email address, the company said.

Facebook said its advertisers must submit the additional documentation by mid-October or it would pause noncompliant ad campaigns.

“We truly understand the importance of protecting elections and have been working for quite some time to bring greater transparency and authenticity to ads about social issues, elections, or politics,” said Katie Harbath, Facebook’s public policy director for global elections.

Over the past few years, Facebook has struggled with questions about election interference on its platform.

The social network has worked to secure its site during elections, setting up so-called war rooms to handle false content and bad ads during the 2018 midterm elections in the United States, as well as the national election in India this year and the EU’s parliamentary elections. It also rolled out the transparency policy on political advertising.