"I categorically deny these rumours, there has been no contact with the London club nor with [Fulham boss] Martin Jol," Jansen told Italian football website www.calciomercato.it.
"He is happy at Roma and his relationship with [coach Zdenek] Zeman is excellent."
The Dutchman, who returned from injury in Tuesday's 3-0 Coppa Italia win over Atalanta, is likely to keep his place for the Serie A clash at Chievo on Sunday.
Roma are joint-fifth in Serie A on 29 points, nine behind league leaders Juventus.
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