The veteran striker, 37, is coming off contract at the end of the season.
Asked if a contract offer has arrived from Barca, Lewandowki told TV3: "We have time, the club knows everything I think. I need time to think; that's clear to both sides.
"Something new comes out in the press every day, but for us it's not important. The most important thing is what we want to do together this season."
He added: "Do I already have a renewal offer? I don't want to talk about my future. The league is what's important. We can talk later."
Meanwhile, on their Champions League exit at the hands of Atletico Madrid, Lewandowski said: "Has it been a tough week? Yes, of course.
"We wanted to be in the Champions League semi-finals, but now we have a few games left and we want to win La Liga."