December 2, 2005 - 1UP Yuuji Horii Interview
As taken from here:
1UP: A lot of fans are still asking for a proper sequel to Chrono Trigger, which was a game you worked on. Would you ever want to work on a sequel? Or would you ever want to see a sequel?
YH: Since everything I would like to do can be done in a Dragon Quest title, the chances of me making a sequel to Chrono Trigger are unlikely. Although as long as the title is interesting I'd definitely love to check it out and play it, even if it's not Chrono Trigger.
From: Interviews