Speaking after his side's 2-1 victory over Reading at the Madejski Stadium on Wednesday, Mourinho said: "We are trying to buy him but the situation is not done at this moment. We will see what happens."
Reports in Spain suggested the two clubs had reached agreement over a £24.5million switch to Stamford Bridge but the London club issued a statement denying this earlier on Wednesday.
The 24-year-old was left out of Sevilla's squad for their Champions League qualifier against AEK Athens, fuelling speculation his career with the UEFA Cup holders is about to come to an end.
"He is determined to go there (Chelsea)," Suarez said, speaking in an interview with BBC Radio Five Live.
"He has spoken in these terms a lot of times, he has said to the press here in Seville that he is 100% determined to go Chelsea.
"He asked for the Seville club to close the agreement with Chelsea as soon as possible. These are his own words."
He added: "We expected yesterday afternoon to be the perfect day to close the agreement but it didn't arrive so it may be two or three days or a maximum of one week before both clubs must find a solution.
"We cannot continue in this way for a long time because the player is suffering a lot here.
"Now we are in a complicated moment between the clubs because both are determined to close a deal but it is not easy to finalise in this case. We will need more time, more patience and more confidence in the clubs.
"We are far enough (apart) to not be close and allow the deal, but close enough to be confident that finally the clubs will be able to reach an agreement for the player."