Singapore airlines has resumed SIN-JFK non stop on the A350. It blocks in at nearly 18 hours.
SIN-JFK routes over the Pacific and western/central arctic for its polar routing.
JFK-SIN returns over the Atlantic and through Russia. It essentially circumnavigates the earth going eastbound the entire time.
https://flightaware.com/live/flight/...825Z/WSSS/KJFK
https://flightaware.com/live/flight/...330Z/KJFK/WSSS