Upvote:2
You will only need a US C Visa (Transit Visa) to transit via any US airport.
Regarding the UK, as an Indian citizen you can transit through the UK as long as you're holding a valid US visa.
From the official gov.uk website:
You donβt need a visa if you have one of the following:
- a visa for Canada, New Zealand, Australia or the USA (this can be used for travel to any country)