The remaining two nuclear-capable bombers then flew southeast and around 9:30 P.M. entered the U.S. northern air defense zone off the coast of Northern California.
Two U.S. F-15 jets were deployed and intercepted the bombers as they eventually flew within 50 miles of the coast before turning around and heading west.
A defense official said the four bombers also were supported by two IL-78 aerial refueling tankers that were used for mid-air refueling during the operation this week.
The Tu-95 is a long-range strike aircraft capable of carrying nuclear cruise missiles. Other versions are equipped with intelligence-gathering sensors and electronic warfare gear. It has a range of around 9,400 miles without refueling.
In addition, Latvia said that Nato fighters that carry out air patrols over the Baltics scrambled a record four times on Thursday after a total of 16 Russian military planes were spotted close to Latvia's airspace.