Half of the 10 countries in Asean have direct flights to India.

The three aviation hubs of Singapore, Bangkok and Kuala Lumpur hold the lion's share of these direct flights, although they are not India's closest neighbours. Singapore has more than 240 flight services a week to India, while Thailand has 270 and Malaysia, 230.

Indonesia and Myanmar also have direct flights to India, but on a very limited scale.

Indonesia's Garuda launched a thrice-weekly direct flight from Jakarta to Mumbai in 2016, while Myanmar has three direct flights a week from Yangon to Kolkata.

VietJet Air said it would begin operating a direct Delhi-Ho Chi Minh flight later this year, after a delay of about a year.

Flights between the Philippines and Mumbai and New Delhi should also restart in the second half of this year. National carrier Philippine Airlines began direct flights to India in March 2011, but cancelled them after eight months, owing to low demand.

In Cambodia and Laos, agreements to open direct flight routes have been signed over the years to little effect. India had agreed to let direct flights with Laos in September 2015, and with Cambodia in September 2016, but neither has come to fruition.

Several airlines fly non-direct routes from Brunei to India. A Centre for Aviation report last year said that Royal Brunei Airlines was mulling over several new destinations in India.