The 74-year-old activist had been fasting for 12 days in a bid to highlight the depth of corruption in public life.
Speaking to NDTV, Khan said: "Anna has not eaten for 12 days... I am worried about you. In everyone's heart, there is concern for you. This will be a long process, and we need Anna's leadership for our struggle. So I urge him here to please end his fast today."
The 3 Idiots star paid tribute to Hazare and said that he supports the anti-corruption Jan Lokpal Bill developed by the Indian activist and his team, which is being debated today in parliament.
Khan said: "I want to hug Anna because he has awakened all of us. This struggle against corruption is all of ours. I have read Anna's Jan Lokpal Bill. I have also read the other version. But Anna's bill is the one I support. Obviously, only parliament can pass this bill. So Anna has tried to ensure it is debated, passed.
"We have elected our MPs. And right now, we are all watching them to see if they give us a tough anti-corruption bill. We have to thank Anna for putting this bill and the issue of corruption in the spotlight. We hope our MPs will not fail us, that they debate this extensively.
"We need to decide as to how we are going to live our lives... Will we give or accept bribes? Will we say no to corruption in our lives?"
The 45-year-old actor sang the song 'Mitwaa' from the film Lagaan for the thousands of people in attendance.
Several other Bollywood stars have pledged their support for Hazare, including Amitabh Bachchan, Rajat Kapoor and Yuvraaj Parashar.
Amitabh Bachchan will reportedly play an anti-corruption figure based on Hazare in Prakash Jha's next release.
Hazare ended his fast this morning after the Indian government passed the Jan Lokpal Bill.