The former Galatasaray boss replaced Walter Mazzarri at San Siro in November with the club ninth in Serie A, but his arrival has failed to have the desired impact.
Mancini has five league wins in his second spell in charge of the club, with Inter still languishing in mid-table with 10 games remaining.
"When I arrived I thought it would be difficult, but I didn't know it was going to be so hard," he told Tuttosport.
"I'm just disappointed because Inter have improved but we're not getting results. However, I'm not a coach under pressure.
"We're just in a moment when everything is going wrong. We have to try to finish the season well to give us a platform to build on for next season.
"At the moment the results aren't coming, and there's the tendency to see everything in a negative light, but we must be able to look a little further.
"We've been working for a few months, and you can’t reinvent a team in such a short space of time."
