MiG-31K.

This is coolbert:

MiG-31K Foxhound [NATO code name]. An air interceptor warplane as a strategic weapon?

From the Internet web site South Front and thanks to same.

"ROLE OF RUSSIA’S NEW STRATEGIC WEAPONS SYSTEMS IN PROVIDING STRATEGIC DETERRENCE"

MiG-31K ten of them now able to function as a stand-off weapons delivery system for the KH-47M2 Kinzhal. Russian hypersonic missile. Kinzhal atomic warhead capable. Image courtesy South Front.

MiG-31 Foxhound [two-seater] based on the original MiG-25 Foxbat. High-speed, high-altitude air interceptor warplane. Foxhound does have a mid-air refueling capability. I wouldn't think Foxhound carrying a Kinzhal would be used in the strategic-range role but rather in the intermediate-range role 

coolbert.