Since the clash, India has made it difficult for Chinese companies to invest, banned hundreds of popular apps and severed passenger routes, although direct cargo flights still operate between the Asian giants.
Direct flights would benefit both economies, but the stakes are higher for China, where a recovery in overseas travel after the COVID-19 pandemic is lagging, while India's aviation sector booms.
Several times over the past year or so, China's government and airlines have asked India's civil aviation authorities to re-establish direct air links, two people with direct knowledge of the matter told Reuters, with one saying China considers this a "big issue".
"We hope the Indian side will work with China in the same direction for the early resumption of direct flights," China's Foreign Ministry told Reuters in a statement last week, adding that resuming flights would be in both countries' interests.