Turkish forward Ciftci has topped the Taysiders’ scoring charts in both of his two seasons with United since moving from NAC Breda, with 31 goals from 81 appearances.
The 23-year-old frontman has been linked with a summer move to Celtic, where he could join up with former Tannadice team-mates Gary Mackay-Steven and Stuart Armstrong.
Celtic, along with Arsenal and Southampton, are also keeping tabs on United youth academy product Souttar following the 18-year-old’s impressive switch from centre-back to a holding midfield role this term.
The Scotland Under-19 cap was just 16 years and 99 days old when he became the club’s youngest ever first-team player back in January 2013.
He has already rejected a move to Barclays Premier League outfit Sunderland but, with only a year to run on both Souttar and Ciftci’s current deals, United are not ready to risk losing them for free in 12 months’ time.
The club were stung by the criticism they received when they were forced to let Armstrong and Mackay-Steven leave for just £2 million back in January as both players decided to let their contracts run down.
A United spokesperson said: “Both players have proved their worth to the team and the club as a whole and merit the extension offer.
“We believe that Dundee United remains the best club for both players to develop and as such have made enhanced longer term offers to the players that reflect their value to Dundee United.”
Meanwhile, the Tangerines insist any move by chairman Stephen Thompson to buy troubled Australian outfit Newcastle Jets is a private affair, and not connected to United.
Reports from down under say the United chief is ready to take over the A-League side after it was placed into voluntary administration.
The United spokesperson confirmed Thompson was interested in taking a stake in the Jets, but added: “Dundee United is not involved in talks with the Newcastle Jets, this is a personal venture for the chairman as part of a consortium.
“Any involvement of Mr Thompson in this or any other venture is entirely his prerogative and the board, which he remains fully committed to, is focused purely on Dundee United FC delivering a positive end to the season and building for next season.”