State Department representatives and a top Soviet Embassy official met again yesterday but failed to break the diplomatic deadlock, now in its sixth day, over the 16-year-old Soviet diplomat's son who may want to defect to this country.

Oleg Sokolov, the second highest official in the embassy, said as he left the State Department after an hour-long meeting that there had been "no progress whatsoever" toward resolving the standoff over U.S. demands to interview the boy before he leaves the country.

State Department spokesman Alan Romberg said earlier yesterday there "is no change in our position" in wanting to interview the youth, Andrei V. Berezhkov, to "ascertain the young man's wishes."

The Soviets remained locked in their position too, with Sokolov insisting that the boy and his family be allowed to leave the United States "without any prior interviewing" by American authorities.

Soviet officials have said the boy is with his mother and father, Valentin M. Berezhkov, a prominent Soviet diplomat. A State Department official said the youth is still believed to be in the Soviet compound on Tunlaw Road in Northwest Washington.

The diplomatic tug-of-war began last Thursday when letters, signed with the boy's name, were received by the White House and The New York Times. The letter to the newspaper said, "I hate my country and it's sic rules and I love your country."

The White House has not released the contents of the letter it received, but a spokesman said the president "has asked to be kept informed" on the negotiations.