A tourist takes a photo of One World Trade Center under construction in New York City on Monday. [Photo/Xinhua]

Photo taken on April 30 shows One World Trade Center under construction in New York City. [Photo/Xinhua]

A bird's-eye view of One World Trade Center under construction in New York City on Monday. [Photo/Xinhua]

NEW YORK - One World Trade Center has become the tallest building in New York City on Monday, overtaking the height of the Empire State Building, according to the Port Authority of New York & New Jersey.

The placement of a column of the 100th floor brought the colossal new steel structure of One World Trade Center tower to a height of 1,271 feet - surpassing the frame of the Empire State Building, which was New York's tallest skyscraper, by 21 feet.

"The New York City skyline is - once again - stretching to new heights. The latest progress at the World Trade Center is a testament to New Yorkers' strength and resolve - and to our belief in a city that is always reaching upward," said Mayor Michael Bloomberg on Monday, one day before the one-year anniversary of the death of Osama bin Laden.

The building stands just north of where the "Twin Towers" once stood, a space which was destroyed during the September 11 terrorist attacks and is now occupied by the National September 11 Memorial and Museum.

The building is expected to reach 1,776 feet when it is finished by early 2014, making it the tallest building in the Western Hemisphere and the third tallest in the world after Burj Khalifa in the United Arab Emirates and Makkah Royal Clock Tower Hotel in Saudi Arabia.

The One World Trade Center building will have three top-floor observation decks. It's first 90 floors will be designated for office space, while the following 10 floors will be reserved for air conditioning, heating, and electrical equipment.