India has not seen significant improvement in debt affordability to justify a rethink on the country's sovereign ratings upgrade, an analyst at Moody's Investors Service said on Thursday.

"I think it is worth bearing in mind that the largest proportion of the Union budget is still servicing interest payments," Senior Vice President Christian de Guzman told Reuters in an interview.

"I think this is why we continue to perhaps keep the rating where it is because there hasn't been as significant improvement in debt affordability." (Reporting by Siddhi Nayak and Swati Bhat)