Newcastle Knights forwards Daniel and Jacob Saifiti have signed two-year contract extensions with the club.

The 21-year-old twins will remain at the Knights through to at least the end of 2020 after showing plenty of promise in their first two seasons in the NRL.

"The club has shown faith in us and hopefully we can repay that," said front-rower Daniel Saifiti, who won the club's Players' Player award in 2017.

"We have been here for two years and I can't imagine being anywhere else."

Jacob Saifiti was also happy to commit his future to the club ahead of the upcoming Rugby League World Cup where he'll represent Fiji.

"I'm excited to play with a lot of new signings next season who can bring that experience that we need," Jacob said.

"We have a strong side on paper and hopefully we'll have a good couple of years ahead of us."