When President John F. Kennedy stated, “Ich bin ein Berliner” in his speech in West Berlin on June 26, 1963, he was primarily denouncing the construction of the Berlin Wall. His statement was a symbolic expression of solidarity with the people of West Berlin, emphasizing the United States' support for West Germany in the face of communist oppression and the division of the city caused by the Wall. Therefore, the correct option is:
The construction of the Berlin Wall.