BERLIN -- Robert Lochner, the interpreter who helped U.S. president John F. Kennedy draft his now-legendary Cold War speech in Berlin, has died aged 84, his daughter said Monday.

Lochner tutored Kennedy in how properly to pronounce the words "Ich bin ein Berliner," a phrase that was greeted with thunderous applause by the hundreds of thousands of people who thronged to see Kennedy.

Lochner, who was born in New York but later settled in Germany, recalled that he was sitting in Kennedy's motorcade as it drove through the city when the president asked him to write the phrase.

In a quiet corner before the speech, they then rehearsed how he should say it.

The president's eight-hour visit on June 26, 1963 came at a critical stage of the Cold War, with Berlin on the front line.

It was only a year since the United States and Soviet Union nearly went to war in the Cuban missile crisis, and two years after East Germany's communist regime had built the Berlin Wall dividing the city in two.

Lochner's daughter said he died suddenly overnight Saturday from pulmonary embolism, or a clot in the lungs.