WASHINGTON (AP) _ A colonel in the Soviet KGB has defected in Greece and has come to the United States with his seven-year old son and a family friend, the State Department said today.

Department deputy spokesman Charles Redman identified the three as Victor P. Gundarev, his son Maxim, and a friend, Galina Gromova. He said they came to the United States at their request.

''I can confirm that Gundarev was a colonel in the KGB posted in Athens at the time of his defection,'' Redman said. He had no other details.