Relatives of seven Americans kidnaped in Lebanon over the past 17 months charged yesterday that the administration's "quiet diplomacy" is not working and called for more action and greater public support to win release of their family members.

John Weir, son of the Rev. Benjamin Weir, a Presbyterian minister abducted in Beirut May 8, 1984, said the seven Americans have not received the same attention that the Reagan administration gave the 39 men on TWA Flight 847 who were hijacked to Beirut last month and held for 17 days.

"There was a task force set up for the TWA hostages that was disbanded the day they got back," John Weir said. "We saw the president and the National Security Council meet on a regular basis to discuss the situation, and people stayed home from vacations. We are just wondering why we saw that for 39 and not for seven."

Weir said that while the administration argues that it is practicing quiet diplomacy, "it's been well over a year and quiet diplomacy has had ample opportunity. I don't know how long we have to hear the quiet diplomacy angle before we have to say it didn't work."

The families of the seven men, the first of whom, William Buckley, was kidnaped March 16, 1984, are here this week to meet with members of Congress to discuss the situation and drum up support.

The group hopes to meet Thursday with Vice President Bush.

"We're asking the administration to stop being spectators in this issue and become participants," said Peggy Say, whose brother, Terry A. Anderson, chief Mideast correspondent for the Associated Press, was abducted in Beirut by three gunmen in March.

Jeremy Levin, Cable News Network's Middle East bureau chief who was held for 11 months in Lebanon before escaping in February, joined the family members at a news conference yesterday and said the seven hostages "were ignored publicly by the government and the press until recently."

Levin said the men's abductors are seeking the release of 17 Arab prisoners held in Kuwait for the 1984 bombings of the American and French embassies.

"The administration knew that exchange was the demand . . . over a year ago," yet would not make that information public, he said.

"Lacking a clear idea of what the seven had been held for, the public has not been energized, as it was in the [TWA] hijack crisis, to communicate with the government its desire that" everything necessary be done to resolve the situation, he said.

In a closed meeting with relatives after the news conference, Robert B. Oakley, director of the State Department's Office for Counter-Terrorism and Emergency Planning, said the administration had hoped the TWA hijacking would serve as a "catalyst" to free the seven. "Unfortunately, we were unsuccessful," he said, according to a statement made available to reporters.

Oakley said the circumstances surrounding the abductions of the seven Americans "make a considerable contrast to the holding and eventual release of the 39 [TWA] hostages."

"Some believe the seven Americans were kidnaped in Lebanon because of a desire by their captors to attack the presence of Americans who really care about Arab peoples and the Arab world, as well as to bring pressure on the U.S. for the release by Kuwait of the convicted terrorist prisoners it holds," he said. "Remember that the expulsion of the American presence was a major objective of those who seized power in Iran from the shah."

State Department spokesman Charles Redman said in a statement: "We believe quiet diplomacy is the best way to proceed and we believe that detailing our efforts to obtain the [hostages'] release could be counterproductive.