BOSTON (AP) _ President Clinton paid tribute to John F. Kennedy today and held out his legacy as an activist in world affairs as a compelling argument for the North American Free Trade Agreement. He said America's duty is to ''reach out rather than inward.''

''Even more than in President Kennedy's day, the line between foreign and domestic interests is rapidly disappearing,'' Clinton said in a ceremony at the Kennedy presidential library.

''We must make clear to the American people that our success at home relies on our engagement abroad, that we must face our problems at home and reach out to the world at the same time.''

Nearing a showdown vote in the House next month, Clinton is intensifying his efforts to muscle the three-nation trade pact through a reluctant Congress. The president is trying to use the argument that NAFTA will promote prosperity at home and abroad to counter arguments from organized labor, Ross Perot and other critics that the pact would hurt American workers and send jobs south to Mexico.

He offered NAFTA as a symbol of America's duty to ''reach out rather than inward'' and said Kennedy would have supported the pact were he still in Congress.

''There is no better example of what we have tried to do to reach out to the world than our attempt to secure an agreement for a North American free trade zone with Canada and Mexico,'' the president said to broad applause.

Clinton said the agreement would create ''200,000 new jobs for this country by 1995, open a vast new market, make 90 million friends and set a stage for moving to embrace all of Latin America ... in a trading unit that will bring prosperity to them and to us.''

Clinton spoke at the dedication of new museum at the Kennedy library, speaking less than a month before the 30th anniversary of Kennedy's assassination in Dallas on Nov. 22, 1963. The new museum is designed to help educate and inspire schoolchildren and others too young to have personal memories of Kennedy or his administration.

Clinton often mentions Kennedy as one of his heroes and loves to relate the story of meeting him as a teen-ager. The young Bill Clinton got a chance to shake Kennedy's hand in the Rose Garden as a Boys Nation delegate in 1963. The president says he came away from the trip with a desire to spend his life in public service.

Clinton was greeted at the Kennedy Library by members of the former president's family, including Jacqueline Kennedy Onassis and their children, Caroline Kennedy Schlossberg and John Jr. Sen. Edward Kennedy, D-Mass., presented Clinton with a set of his late brother's writings.

When Clinton announced that at least one member of the Kennedy family - Rep. Joe Kennedy, D-Mass., supported the free trade agreement, the congressman's uncle - Sen. Kennedy - grimaced and then broke into a broad grin and lifted his tie over his head as if it were a noose. Sen. Kennedy, a strong supporter of organized labor, has not endorsed the pact.

NAFTA would eliminate most barriers to open trade with Mexico and Canada. The pact is in deep trouble in the House because of strong opposition of organized labor, which contends it would encourage U.S. companies to move jobs to Mexico in pursuit of lower wages.

Clinton's visit to the Kennedy Library was the second of three events on a trip outside Washington designed to mobilize support for NAFTA and push his health-care plan.

This afternoon, the president was visiting Gillette Co. in South Boston. The company, known for razors and personal hygiene products, expects its export business to expand if NAFTA is approved.

On Thursday, Clinton urged business leaders in New York City to mobilize for an ''all hands on deck'' effort to push the trade agreement through Congress. Addressing The Wall Street Journal's Conference on the Americas, Clinton acknowledged that early on he had misjudged the strength of opposition to the agreement.

''I really believed that the cause was so self-evidently in the interests of the United States that, after a little bit of smoke and stirring around, the votes would rather quickly line up in behalf of what was plainly in our short- and long-term national interests,'' he said. ''It is no secret that that has not happened.''