It is being fuded as part of SLS program
These will replace the SRBs. each Liquid fueled booster (LFB) will have two f-1 engines. The booster is tentatively named Pyrios, after one of the fiery horses that pulled the god Apollo's chariot; the engine is being called the F-1B.
Now if you recall, Energiya was similar, in that it had hydrogen burning (RD-0120) engines were placed under the Russian external Tank (Energiya itself) rendering Buran just one of many possible payloads. The booster used four thin strap-ons each with one RD-170 (four nozzle) engine. Pyrios will be fatter, and have two F-1 B engines