The rules, expected to be announced by the year-end and with details yet to be hammered out, would establish a legal basis for controlling news dissemination on platforms like Facebook and YouTube while placing a significant moderation burden on platform providers, two of the sources added.
The sources asked not to be identified, as discussions about the new rules remain confidential.
Vietnam's Ministry of Information and Communications and Ministry of Foreign Affairs did not immediately respond to requests for comment.
"The government wants to fix what it sees as the 'news-lisation' of social media," said one source familiar with the talks. "News-lisation", or báo hoá, is a term used by the authorities to describe the misleading of users into thinking that social media accounts are authorised news outlets.
Government officials have been holding confidential meetings with popular social media and internet firms to brief them on which types of accounts will be allowed to post news content under the new rules, according to the sources.
Authorities would be able to order social media companies to ban accounts that break those rules, they said.
Vietnam's ruling Communist Party already maintains tight media censorship and tolerates little dissent, with one of the world's most stringent internet regimes and national guidelines on social media behaviour.
Two sources with direct knowledge told Reuters that more rules on internet and social media platforms would be introduced around the fourth quarter of 2022 to early 2023.
As tech-savvy young Vietnamese increasingly turn to social media for information, those platforms have become a target for government efforts to restrict the flow of news from unauthorised sources.
Vietnam is a top-10 market globally for Facebook with 60 million to 70 million users, according to 2021 data, and sources familiar with the matter said it generates around $1 billion in annual revenue for the company - surpassing France.
YouTube has 60 million users in Vietnam and TikTok has 20 million, according to 2021 government estimates, although Twitter remains a relatively small player.
Meta Platforms Inc, owner of Facebook, and Twitter Inc declined to comment. Alphabet Inc's Google and YouTube did not respond to requests for comment. TikTok said in a statement that it addresses content violations based on applicable laws and with adherence to its guidelines, but did not comment on pending Vietnam regulations.
The Vietnamese government had adopted in July a set of non-binding guidelines on what qualifies as news outlets, including criteria to distinguish "real" and "fake" news outlets, warning that some social networking sites include accounts that mislead users into thinking they are newspapers.
Those guidelines are expected to be incorporated into the new rules, which will be binding. The authorities are also expected to implement new rules that would require social media platforms to immediately take down content deemed to harm national security, and to remove illegal content within 24 hours, sources familiar with the matter said.
Sources told Reuters in April that the new rules, which were originally planned for July, reflected the government's dissatisfaction with social media platforms' take-down rates.
This will be done through amendments to the country's main internet law.
Vietnam in August also issued a new regulation, due to come into effect from October, that will require technology firms to store users' data locally and to set up local offices.
(Reporting by Fanny Potkin in Singapore and Phuong Nguyen in Hanoi; Editing by Edmund Klamann)
By Fanny Potkin and Phuong Nguyen