Former Soviet Foreign Minister Eduard A. Shevardnadze, who helped end the Cold War and launch a new era in U.S.-Soviet relations before quitting abruptly 4 1/2 months ago, is going public again.

Shevardnadze was opening a three-week speaking tour of the United States on Monday with an address to the 75th anniversary celebration of the Brookings Institution, a pioneer Washington think tank.He also planned to meet and have lunch with his one-time counterpart, Secretary of State James A. Baker III.

But a scheduled afternoon meeting with President Bush was thrown into doubt when Bush remained hospitalized overnight with an irregular heartbeat that began Saturday.

Shevardnadze's visit to the United States, his first venture back into the limelight since his surprise resignation last Dec. 20, is designed to raise money for his new, independent Moscow think tank called the Foreign Policy Association.

The former foreign minister and close adviser to Soviet President Mikhail S. Gorbachev got away a day late due to the cancellation of his flight from Moscow to New York, which precluded him from appearing on Sunday's television talk shows.

Shevardnadze told reporters upon his arrival at John F. Kennedy International Airport in New York that arms control negotiators should speed up their talks to open the way for another U.S.-Soviet summit soon.

Bush and Gorbachev had been set to meet in Moscow in February but put off their summit because of the Persian Gulf war and the failure of the two sides to settle their remaining differences on the nearly complete treaty to slash both sides' long-range nuclear weapons arsenals.

The White House and Kremlin said at the time that the meeting would be rescheduled before the end of June. But no progress has been reported on the strategic arms talks, and no new summit date has been set.

Asked if superpower relations have cooled, Shevardnadze said Sunday, "I'm not sure there has been such a chill. . . . If there has been a certain pause in our relationship, it is a normal phenomenon."

He predicted the summit would occur "in due course."