Eirik Horneland was strongly linked with a move to Pittodrie after losing his job at French Ligue 2 club Saint-Etienne at the end of January.
But the return of former assistant manager Tony Docherty on 13 February suggested a permanent appointment is still some way off.
Cormack says sporting director Lutz Pfannenstiel had talks with "several strong candidates from both the UK and overseas".
The chairman went on to explain that "most candidates were not available to begin work immediately".
Via a statement, he said: "Increasingly, coaches want a full pre-season to properly implement their ideas and philosophy, particularly those relocating from abroad.
"Due to unforeseen circumstances the final stage of the process is taking longer than we expected.
"Make no mistake, we are determined to secure the right head coach, someone who can provide stability and long-term success for Aberdeen FC."

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