"We are very supportive of Lee and he is very focused on moving Town up the leagues," Jarvis told BBC Radio Leeds.
"We believe Lee will deliver what we want to achieve, be it this year, next year or the year after that."
This is Clark's first full season as a manager and he has kept Town in the top eight for the majority of the season. But with just 10 games remaining some fans are getting nervous with Town winless in their last four matches.
"I have worked in football 20 years now and I've never met anyone as focused as Lee to gain success. We know what he and the backroom staff are capable of," explained Jarvis.
"Football always brings pressure to succeed for people both on and off the field. We want success at this club and success will come. We certainly hope it is sooner rather than later.
"I'm certain all the board are very supportive of Lee and together we will work together to achieve our goals. I'm certain Lee is going to be a successful manager here at Huddersfield Town."
Source: BBC Sport
Source: BBC Sport