According to a Starfleet Academy simulator scenario, the Koth are a new species with whom the Federation had First contact as of late 23rd century. The USS Excalibur was assigned to deliver Ambassador Robert Fox to the meeting at the Janus sector where the Koth had also a meeting with the Romulans.
While there, the Romulans attempted to avert the meeting with Fox, so they feigned a message to divert the Excalibur to the Galta sector. If the cadet who serves as Captain falls in, he/she will have to fight off a Romulan warbird and then apologise to the Koth for the delay. (TOS video game: Starfleet Academy Starship Bridge Simulator)