bishwanth form USA with nepali passport

Hello, my flight itinerary is like this China Eastern Flight 768 332

01:40pm Tue, Aug 28 Take-off: San Francisco (SFO)
11:15pm Wed, Aug 29 Landing: Kunming (KMG)
Layover: 15h 5m (Long connection)
02:20pm Thu, Aug 30 Take-off: Kunming (KMG)
03:15pm Thu, Aug 30 Landing: Kathmandu (KTM)

Do i need transit visa?
thanks in advance