The stepson of missing Soviet dissident Andrei Sakharov ended a 14-day hunger strike yesterday after, he said, the State Department told him the fate of Sakharov is a "high priority issue."

"I was assured that the State Department will use every opportunity to resolve the case of my parents before the November summit," said Alex Semyonov, 29, speaking at a Capitol Hill news conference.

"I think the continuation of my fast will not serve the purpose of helping my parents, said Semyonov, flanked by his 85-year-old grandmother.

Both relatives urged the Soviets to make the whereabouts of Sakharov, a Nobel Peace Prize winner, and his wife, Yelenna Bonner, known before the Geneva summit.

Sakharov, a nuclear physicist who challenged Soviet policy and crusaded for human rights in that country, has not been seen for more than six months. He and his wife have been living in exile in the closed town of Gorki, north of Moscow.

Also at the press conference, Sens. Alfonse D'Amato (R-N.Y), Don Reigle (D-Mich.) and George Mitchell (D-Maine) said that any agreements at the summit will be greatly diminished if the Soviets do not let Sakharov establish contact with his family.