The companies’ security teams met representatives from the Federal Bureau of Investigation, the Office of the Director of National Intelligence, and the Department of Homeland Security at Facebook’s headquarters in Menlo Park.

“The purpose was to build on previous discussions and further strengthen strategic collaboration regarding the security of the 2020 U.S. state, federal, and presidential elections,” Nathaniel Gleicher, Facebook’s head of cybersecurity policy, said in a statement.

“Specifically, attendees talked about how industry and government could improve how we share information and coordinate our response to better detect and deter threats.”

Social media companies are under pressure to ramp up security after what U.S. intelligence agencies have called an extensive Russian cyber-influence operation aimed at helping President Donald Trump get elected in 2016. Russia has repeatedly denied the allegations.

“This is a joint effort in response to a shared threat, and we are committed to doing our part,” a Twitter spokeswoman told Reuters in a statement.

Microsoft and Google also confirmed their attendance at the meeting.

“At Google, we’ve invested in robust systems to detect phishing and hacking attempts, identify foreign interference on our platforms, and protect campaigns from digital attacks. But technology is only part of the solution,” said Richard Salgado, Google’s director of law enforcement and information security.

“It is crucial that industry, law enforcement and others collaborate to prevent any threats to the integrity of our elections.”